feat: implement Famicom-style MML composer MCP server

- Add FastMCP server with compose_mml tool

- Support ppmck and pyxel MML syntax

- Add lexer and parsers for both formats

- Add NES APU-style synthesizer (pulse/triangle/noise) to WAV

- Add MML templates (basic/melody/chord/drum/empty) for both modes

- Add tests for lexer, parser, and server

- Support stdio, http, sse, streamable-http transports

- Update README, pyproject.toml, and .gitignore

9 files changed, 2281 insertions, 0 deletions

diff --git a/src/__init__.py b/src/mml_composemusic_mcp/__init__.py
index e69de29..e69de29 100644
--- a/src/__init__.py
+++ b/src/mml_composemusic_mcp/__init__.py
diff --git a/src/mml_composemusic_mcp/ir.py b/src/mml_composemusic_mcp/ir.py
new file mode 100644
index 0000000..05ef37a
--- /dev/null
+++ b/src/mml_composemusic_mcp/ir.py
@@ -0,0 +1,185 @@
+"""Intermediate representation for MML NoteSequence and errors."""
+
+from dataclasses import dataclass, field
+from enum import Enum
+from typing import Any
+
+
+class ErrorCode(Enum):
+    """Machine-readable error codes."""
+
+    SYNTAX_INVALID_TOKEN = "SYNTAX_INVALID_TOKEN"
+    SYNTAX_INVALID_NUMBER = "SYNTAX_INVALID_NUMBER"
+    SYNTAX_VALUE_OUT_OF_RANGE = "SYNTAX_VALUE_OUT_OF_RANGE"
+    SYNTAX_UNEXPECTED_TOKEN = "SYNTAX_UNEXPECTED_TOKEN"
+    SYNTAX_UNTERMINATED_REPEAT = "SYNTAX_UNTERMINATED_REPEAT"
+    SYNTAX_UNMATCHED_REPEAT_END = "SYNTAX_UNMATCHED_REPEAT_END"
+    SYNTAX_UNTERMINATED_TIE = "SYNTAX_UNTERMINATED_TIE"
+    SYNTAX_INVALID_TRACK_HEADER = "SYNTAX_INVALID_TRACK_HEADER"
+    SYNTAX_DUPLICATE_TRACK = "SYNTAX_DUPLICATE_TRACK"
+    SYNTAX_EMPTY_TRACK = "SYNTAX_EMPTY_TRACK"
+    SYNTAX_NOTE_OUT_OF_RANGE = "SYNTAX_NOTE_OUT_OF_RANGE"
+    SYNTAX_CHANNEL_MISMATCH = "SYNTAX_CHANNEL_MISMATCH"
+    SYNTAX_UNTERMINATED_HEADER = "SYNTAX_UNTERMINATED_HEADER"
+    SYNTAX_UNDEFINED_REFERENCE = "SYNTAX_UNDEFINED_REFERENCE"
+
+    SYSTEM_SYNTHESIS_FAILED = "SYSTEM_SYNTHESIS_FAILED"
+    SYSTEM_WAV_WRITE_FAILED = "SYSTEM_WAV_WRITE_FAILED"
+    SYSTEM_INTERNAL_ERROR = "SYSTEM_INTERNAL_ERROR"
+
+
+@dataclass
+class ErrorDetail:
+    """Structured error/warning detail."""
+
+    code: ErrorCode
+    line: int
+    column: int
+    message: str
+    severity: str  # "error" | "warning"
+    hint: str = ""
+    context: str = ""
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "code": self.code.value,
+            "line": self.line,
+            "column": self.column,
+            "message": self.message,
+            "severity": self.severity,
+            "hint": self.hint,
+            "context": self.context,
+        }
+
+
+@dataclass
+class NoteEvent:
+    type: str = "note"
+    tick_position: int = 0
+    duration: int = 0
+    note_number: int = 69
+    velocity: int = 15
+    duty: int = 2
+    gate_time: float = 1.0
+
+
+@dataclass
+class RestEvent:
+    type: str = "rest"
+    tick_position: int = 0
+    duration: int = 0
+
+
+@dataclass
+class VolumeEvent:
+    type: str = "volume"
+    tick_position: int = 0
+    value: int = 15
+
+
+@dataclass
+class DutyEvent:
+    type: str = "duty"
+    tick_position: int = 0
+    value: int = 2
+
+
+@dataclass
+class TempoEvent:
+    type: str = "tempo"
+    tick_position: int = 0
+    bpm: int = 120
+
+
+@dataclass
+class RepeatEvent:
+    type: str = "repeat"
+    tick_position: int = 0
+    start_tick: int = 0
+    end_tick: int = 0
+    repeat_count: int = 1
+    duration: int = 0
+
+
+@dataclass
+class EnvelopeEvent:
+    type: str = "envelope"
+    tick_position: int = 0
+    slot: int = 0
+    points: list[dict[str, int]] = field(default_factory=list)
+
+
+@dataclass
+class VibratoEvent:
+    type: str = "vibrato"
+    tick_position: int = 0
+    slot: int = 0
+    params: dict[str, int] = field(default_factory=dict)
+
+
+@dataclass
+class GlideEvent:
+    type: str = "glide"
+    tick_position: int = 0
+    slot: int = 0
+    params: dict[str, int] = field(default_factory=dict)
+
+
+Event = (
+    NoteEvent
+    | RestEvent
+    | VolumeEvent
+    | DutyEvent
+    | TempoEvent
+    | RepeatEvent
+    | EnvelopeEvent
+    | VibratoEvent
+    | GlideEvent
+)
+
+
+@dataclass
+class ChannelSequence:
+    channel_type: str = "pulse"
+    events: list[Event] = field(default_factory=list)
+    total_ticks: int = 0
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "channel_type": self.channel_type,
+            "events": [event_to_dict(e) for e in self.events],
+            "total_ticks": self.total_ticks,
+        }
+
+
+@dataclass
+class NoteSequence:
+    version: str = "1.0"
+    bpm: int = 120
+    ticks_per_quarter: int = 192
+    channels: dict[str, ChannelSequence] = field(
+        default_factory=lambda: {
+            "Pulse1": ChannelSequence("pulse"),
+            "Pulse2": ChannelSequence("pulse"),
+            "Triangle": ChannelSequence("triangle"),
+            "Noise": ChannelSequence("noise"),
+        }
+    )
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "version": self.version,
+            "bpm": self.bpm,
+            "ticks_per_quarter": self.ticks_per_quarter,
+            "channels": {k: v.to_dict() for k, v in self.channels.items()},
+        }
+
+
+def event_to_dict(event: Event) -> dict[str, Any]:
+    if isinstance(
+        event, (NoteEvent, RestEvent, VolumeEvent, DutyEvent, TempoEvent, RepeatEvent)
+    ):
+        return event.__dict__
+    if isinstance(event, (EnvelopeEvent, VibratoEvent, GlideEvent)):
+        return event.__dict__
+    raise TypeError(f"Unsupported event type: {type(event)}")
diff --git a/src/mml_composemusic_mcp/lexer.py b/src/mml_composemusic_mcp/lexer.py
new file mode 100644
index 0000000..05861cf
--- /dev/null
+++ b/src/mml_composemusic_mcp/lexer.py
@@ -0,0 +1,314 @@
+"""Common lexer for MML."""
+
+from collections.abc import Iterable
+from dataclasses import dataclass
+from enum import Enum, auto
+
+
+class TokenType(Enum):
+    NOTE = auto()
+    REST = auto()
+    OCTAVE = auto()
+    OCTAVE_UP = auto()
+    OCTAVE_DOWN = auto()
+    LENGTH = auto()
+    VOLUME = auto()
+    DUTY = auto()
+    TEMPO = auto()
+    GATE_TIME = auto()
+    TIE = auto()
+    REPEAT_START = auto()
+    REPEAT_END = auto()
+    BAR = auto()
+    TRACK_HEADER = auto()
+    HEADER = auto()
+    COMMENT = auto()
+    NUMBER = auto()
+    SHARP = auto()
+    FLAT = auto()
+    DOT = auto()
+    TEXT = auto()
+    AT = auto()
+    TRANSPOSE = auto()
+    DETUNE = auto()
+    EXT_CMD = auto()  # @ENV, @VIB, @GLI
+    EOF = auto()
+
+
+@dataclass
+class Token:
+    type: TokenType
+    value: str
+    line: int
+    column: int
+    raw: str = ""
+
+
+def _track_header_char(ch: str) -> bool:
+    return ch.isupper() and ch in "ABTNL"
+
+
+class Lexer:
+    def __init__(self, source: str, mode: str = "ppmck") -> None:
+        self.source = source
+        self.mode = mode.lower()
+        self.tokens: list[Token] = []
+        self.line = 1
+        self.column = 1
+        self.pos = 0
+
+    def _peek(self, offset: int = 0) -> str:
+        idx = self.pos + offset
+        if idx >= len(self.source):
+            return ""
+        return self.source[idx]
+
+    def _advance(self) -> str:
+        ch = self.source[self.pos]
+        self.pos += 1
+        if ch == "\n":
+            self.line += 1
+            self.column = 1
+        else:
+            self.column += 1
+        return ch
+
+    def _skip_whitespace(self) -> None:
+        while self.pos < len(self.source) and self.source[self.pos] in " \t\r":
+            self._advance()
+
+    def _read_number(self) -> str:
+        start = ""
+        while self.pos < len(self.source) and self.source[self.pos].isdigit():
+            start += self._advance()
+        return start
+
+    def _read_until_newline(self) -> str:
+        start = ""
+        while self.pos < len(self.source) and self.source[self.pos] not in "\r\n":
+            start += self._advance()
+        return start
+
+    def _read_header_value(self) -> str:
+        value = ""
+        if self._peek() == '"':
+            self._advance()
+            while self.pos < len(self.source) and self._peek() not in '"\r\n':
+                value += self._advance()
+            if self._peek() == '"':
+                self._advance()
+            else:
+                # Return raw unterminated header; parser reports error
+                pass
+        return value
+
+    def tokenize(self) -> list[Token]:
+        while self.pos < len(self.source):
+            self._skip_whitespace()
+            if self.pos >= len(self.source):
+                break
+            ch = self._peek()
+            start_line = self.line
+            start_col = self.column
+
+            if self.mode == "ppmck":
+                self._tokenize_ppmck(ch, start_line, start_col)
+            else:
+                self._tokenize_pyxel(ch, start_line, start_col)
+        self.tokens.append(Token(TokenType.EOF, "", self.line, self.column))
+        return self.tokens
+
+    def _emit(self, ttype: TokenType, value: str, raw: str = "") -> None:
+        self.tokens.append(
+            Token(ttype, value, self.line, self.column - len(raw), raw or value)
+        )
+
+    def _tokenize_ppmck(self, ch: str, start_line: int, start_col: int) -> None:  # noqa: ARG002
+        if ch == "\n":
+            self._advance()
+            return
+        if ch == ";":
+            raw = self._read_until_newline()
+            self._emit(TokenType.COMMENT, raw, raw)
+            return
+        if ch == "#":
+            raw = "#" + self._read_until_newline()
+            self._emit(TokenType.HEADER, raw, raw)
+            return
+        if ch == "|":
+            self._advance()
+            self._emit(TokenType.BAR, "|", "|")
+            return
+        if ch == ">":
+            self._advance()
+            self._emit(TokenType.OCTAVE_UP, ">", ">")
+            return
+        if ch == "<":
+            self._advance()
+            self._emit(TokenType.OCTAVE_DOWN, "<", "<")
+            return
+        if ch == "&":
+            self._advance()
+            self._emit(TokenType.TIE, "&", "&")
+            return
+        if ch == "[":
+            self._advance()
+            self._emit(TokenType.REPEAT_START, "[", "[")
+            return
+        if ch == "]":
+            self._advance()
+            count = self._read_number()
+            self._emit(TokenType.REPEAT_END, count, "]" + count)
+            return
+        if ch == ".":
+            self._advance()
+            self._emit(TokenType.DOT, ".", ".")
+            return
+        if ch == "+":
+            self._advance()
+            self._emit(TokenType.SHARP, "+", "+")
+            return
+        if ch == "-":
+            self._advance()
+            self._emit(TokenType.FLAT, "-", "-")
+            return
+        if ch.isdigit():
+            num = self._read_number()
+            self._emit(TokenType.NUMBER, num, num)
+            return
+        if _track_header_char(ch):
+            raw = self._advance()
+            self._emit(TokenType.TRACK_HEADER, raw.upper(), raw)
+            return
+        if ch.isalpha():
+            cmd = self._advance()
+            if ch in "olvtq":
+                num = self._read_number()
+                raw = cmd + num
+                if ch == "o":
+                    self._emit(TokenType.OCTAVE, num, raw)
+                elif ch == "l":
+                    self._emit(TokenType.LENGTH, num, raw)
+                elif ch == "v":
+                    self._emit(TokenType.VOLUME, num, raw)
+                elif ch == "t":
+                    self._emit(TokenType.TEMPO, num, raw)
+                elif ch == "q":
+                    self._emit(TokenType.DUTY, num, raw)
+                return
+            # Note commands
+            note = ch.lower()
+            if note in "cdefgabr":
+                if note == "r":
+                    self._emit(TokenType.REST, note, note)
+                else:
+                    self._emit(TokenType.NOTE, note, note)
+                return
+            # Unknown command
+            self._emit(TokenType.TEXT, cmd, cmd)
+            return
+        # Fallback invalid char
+        raw = self._advance()
+        self._emit(TokenType.TEXT, raw, raw)
+
+    def _tokenize_pyxel(self, ch: str, start_line: int, start_col: int) -> None:  # noqa: ARG002
+        if ch == "\n":
+            self._advance()
+            return
+        if ch == "|":
+            self._advance()
+            self._emit(TokenType.BAR, "|", "|")
+            return
+        if ch == ">":
+            self._advance()
+            self._emit(TokenType.OCTAVE_UP, ">", ">")
+            return
+        if ch == "<":
+            self._advance()
+            self._emit(TokenType.OCTAVE_DOWN, "<", "<")
+            return
+        if ch == "&":
+            self._advance()
+            self._emit(TokenType.TIE, "&", "&")
+            return
+        if ch == "[":
+            self._advance()
+            self._emit(TokenType.REPEAT_START, "[", "[")
+            return
+        if ch == "]":
+            self._advance()
+            count = self._read_number()
+            self._emit(TokenType.REPEAT_END, count, "]" + count)
+            return
+        if ch == ".":
+            self._advance()
+            self._emit(TokenType.DOT, ".", ".")
+            return
+        if ch == "+":
+            self._advance()
+            self._emit(TokenType.SHARP, "+", "+")
+            return
+        if ch == "-":
+            self._advance()
+            self._emit(TokenType.FLAT, "-", "-")
+            return
+        if ch.isdigit():
+            num = self._read_number()
+            if self._peek() == ":":
+                self._advance()
+                self._emit(TokenType.TRACK_HEADER, num, num + ":")
+            else:
+                self._emit(TokenType.NUMBER, num, num)
+            return
+        if ch == "@":
+            self._advance()
+            if self.source[self.pos : self.pos + 3].upper() in ("ENV", "VIB", "GLI"):
+                ext = self.source[self.pos : self.pos + 3].upper()
+                self.pos += 3
+                self.column += 3
+                raw = "@" + ext
+                self._emit(TokenType.EXT_CMD, ext, raw)
+                return
+            num = self._read_number()
+            self._emit(TokenType.AT, num, "@" + num)
+            return
+        if ch.isalpha():
+            cmd = self._advance()
+            if cmd in "OLVTQKY":
+                num = self._read_number()
+                raw = cmd + num
+                if cmd == "O":
+                    self._emit(TokenType.OCTAVE, num, raw)
+                elif cmd == "L":
+                    self._emit(TokenType.LENGTH, num, raw)
+                elif cmd == "V":
+                    self._emit(TokenType.VOLUME, num, raw)
+                elif cmd == "T":
+                    self._emit(TokenType.TEMPO, num, raw)
+                elif cmd == "Q":
+                    self._emit(TokenType.GATE_TIME, num, raw)
+                elif cmd == "K":
+                    self._emit(TokenType.TRANSPOSE, num, raw)
+                elif cmd == "Y":
+                    self._emit(TokenType.DETUNE, num, raw)
+                return
+            note = cmd.upper()
+            if note in "CDEFGABR":
+                if note == "R":
+                    self._emit(TokenType.REST, note, note)
+                else:
+                    self._emit(TokenType.NOTE, note, note)
+                return
+            self._emit(TokenType.TEXT, cmd, cmd)
+            return
+        # Fallback
+        raw = self._advance()
+        self._emit(TokenType.TEXT, raw, raw)
+
+
+def tokenize(source: str, mode: str = "ppmck") -> list[Token]:
+    return Lexer(source, mode).tokenize()
+
+
+def iter_token_text(tokens: Iterable[Token]) -> str:
+    return " ".join(f"{t.type.name}:{t.value}" for t in tokens)
diff --git a/src/mml_composemusic_mcp/parser_base.py b/src/mml_composemusic_mcp/parser_base.py
new file mode 100644
index 0000000..0427a4c
--- /dev/null
+++ b/src/mml_composemusic_mcp/parser_base.py
@@ -0,0 +1,92 @@
+"""Base parser utilities shared between ppmck and pyxel parsers."""
+
+from dataclasses import dataclass
+
+from .ir import ErrorCode, ErrorDetail
+from .lexer import Token, TokenType
+
+
+@dataclass
+class ParserContext:
+    tokens: list[Token]
+    pos: int = 0
+    errors: list[ErrorDetail] = None  # type: ignore[assignment]
+
+    def __post_init__(self) -> None:
+        if self.errors is None:
+            self.errors = []
+
+    def peek(self, offset: int = 0) -> Token:
+        idx = self.pos + offset
+        if idx >= len(self.tokens):
+            return self.tokens[-1]
+        return self.tokens[idx]
+
+    def advance(self) -> Token:
+        token = self.peek()
+        self.pos += 1
+        return token
+
+    def match(self, *types: TokenType) -> Token | None:
+        token = self.peek()
+        if token.type in types:
+            return self.advance()
+        return None
+
+    def expect(self, *types: TokenType) -> Token | None:
+        return self.match(*types)
+
+    def add_error(
+        self,
+        code: ErrorCode,
+        line: int,
+        column: int,
+        message: str,
+        severity: str,
+        hint: str = "",
+        context: str = "",
+    ) -> None:
+        self.errors.append(
+            ErrorDetail(
+                code=code,
+                line=line,
+                column=column,
+                message=message,
+                severity=severity,
+                hint=hint,
+                context=context,
+            )
+        )
+
+
+class ParserError(Exception):
+    pass
+
+
+def length_value_to_ticks(length: int, dots: int, ticks_per_quarter: int = 192) -> int:
+    base = ticks_per_quarter * 4 // length
+    total = base
+    add = base
+    for _ in range(dots):
+        add //= 2
+        total += add
+    return total
+
+
+NOTE_OFFSET = {
+    "c": 0,
+    "d": 2,
+    "e": 4,
+    "f": 5,
+    "g": 7,
+    "a": 9,
+    "b": 11,
+}
+
+
+def note_to_midi(note: str, octave: int, accidental: int = 0) -> int:
+    return (octave + 1) * 12 + NOTE_OFFSET[note] + accidental
+
+
+def clamp(value: int, min_val: int, max_val: int) -> int:
+    return max(min_val, min(value, max_val))
diff --git a/src/mml_composemusic_mcp/parser_ppmck.py b/src/mml_composemusic_mcp/parser_ppmck.py
new file mode 100644
index 0000000..c2a1fa3
--- /dev/null
+++ b/src/mml_composemusic_mcp/parser_ppmck.py
@@ -0,0 +1,451 @@
+"""PPMCK-style MML parser."""
+
+from .ir import (
+    DutyEvent,
+    ErrorCode,
+    ErrorDetail,
+    NoteEvent,
+    NoteSequence,
+    RepeatEvent,
+    RestEvent,
+    TempoEvent,
+)
+from .lexer import Token, TokenType
+from .parser_base import (
+    ParserContext,
+    clamp,
+    length_value_to_ticks,
+    note_to_midi,
+)
+
+CHANNEL_MAP = {
+    "A": "Pulse1",
+    "B": "Pulse2",
+    "T": "Triangle",
+    "N": "Noise",
+}
+PULSE_CHANNELS = {"Pulse1", "Pulse2"}
+
+
+class PpmckParser:
+    def __init__(self, source: str, tokens: list[Token]) -> None:
+        self.source = source
+        self.ctx = ParserContext(tokens)
+        self.note_sequence = NoteSequence()
+        self.current_channel: str | None = None
+        self.octave = 4
+        self.default_length = 4
+        self.velocity = 15
+        self.duty = 2
+        self.tick_position = 0
+        self.headers: list[tuple[str, str]] = []
+        self.loop_start: int | None = None
+        self.tracks_seen: set[str] = set()
+
+    def _context_line(self, token: Token) -> str:
+        lines = self.source.splitlines()
+        if 1 <= token.line <= len(lines):
+            return lines[token.line - 1]
+        return ""
+
+    def parse(self) -> tuple[NoteSequence, list[ErrorDetail]]:
+        while self.ctx.peek().type != TokenType.EOF:
+            token = self.ctx.peek()
+            if token.type == TokenType.HEADER:
+                self._parse_header()
+                continue
+            if token.type == TokenType.COMMENT:
+                self.ctx.advance()
+                continue
+            if token.type == TokenType.TRACK_HEADER:
+                self._parse_track_header()
+                continue
+            if self.current_channel is None:
+                self.ctx.advance()
+                continue
+            self._parse_statement()
+
+        self._validate_tracks()
+
+        if self.loop_start is not None:
+            max_tick = max(
+                ch.total_ticks for ch in self.note_sequence.channels.values()
+            )
+            for ch in self.note_sequence.channels.values():
+                ch.events.append(
+                    RepeatEvent(
+                        start_tick=self.loop_start,
+                        end_tick=max_tick,
+                        repeat_count=0,
+                    )
+                )
+
+        for ch in self.note_sequence.channels.values():
+            ch.total_ticks = max(
+                (e.tick_position + getattr(e, "duration", 0) for e in ch.events),
+                default=0,
+            )
+
+        return self.note_sequence, self.ctx.errors
+
+    def _parse_header(self) -> None:
+        token = self.ctx.advance()
+        raw = token.value
+        parts = raw.split(None, 1)
+        key = parts[0] if parts else raw
+        value = ""
+        if len(parts) > 1 and parts[1].startswith('"'):
+            value = parts[1].strip('"')
+            if not parts[1].endswith('"') or parts[1] == '"':
+                self.ctx.add_error(
+                    code=ErrorCode.SYNTAX_UNTERMINATED_HEADER,
+                    line=token.line,
+                    column=token.column,
+                    message=f"ヘッダー '{key}' の引用符が閉じられていません。",
+                    severity="error",
+                    hint='二重引用符 " で値を閉じてください。例: #TITLE "My Song"',
+                    context=self._context_line(token),
+                )
+        self.headers.append((key, value))
+
+    def _parse_track_header(self) -> None:
+        token = self.ctx.advance()
+        ch = token.value.upper()
+        if ch == "L":
+            self.loop_start = 0
+            return
+        if ch not in CHANNEL_MAP:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_INVALID_TRACK_HEADER,
+                line=token.line,
+                column=token.column,
+                message=f"無効なトラックヘッダー '{ch}' です。",
+                severity="error",
+                hint="A, B, T, N, L のいずれかを使用してください。",
+                context=self._context_line(token),
+            )
+            self.current_channel = None
+            return
+        self.current_channel = CHANNEL_MAP[ch]
+        if self.current_channel in self.tracks_seen:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_DUPLICATE_TRACK,
+                line=token.line,
+                column=token.column,
+                message=f"トラック '{ch}' が複数回定義されています。",
+                severity="error",
+                hint="各トラックは1回のみ定義できます。重複定義を削除してください。",
+                context=self._context_line(token),
+            )
+        self.tracks_seen.add(self.current_channel)
+        self.octave = 4
+        self.default_length = 4
+        self.velocity = 15
+        self.duty = 2
+        self.tick_position = 0
+
+    def _parse_statement(self) -> None:
+        token = self.ctx.peek()
+        handlers = {
+            TokenType.NOTE: self._parse_note,
+            TokenType.REST: self._parse_rest,
+            TokenType.OCTAVE: self._parse_octave,
+            TokenType.OCTAVE_UP: self._parse_octave_up,
+            TokenType.OCTAVE_DOWN: self._parse_octave_down,
+            TokenType.LENGTH: self._parse_length,
+            TokenType.VOLUME: self._parse_volume,
+            TokenType.DUTY: self._parse_duty,
+            TokenType.TEMPO: self._parse_tempo,
+            TokenType.TIE: self._parse_tie,
+            TokenType.REPEAT_START: self._parse_repeat_start,
+            TokenType.REPEAT_END: self._parse_repeat_end,
+            TokenType.BAR: self._parse_bar,
+            TokenType.COMMENT: lambda: self.ctx.advance(),
+        }
+        handler = handlers.get(token.type)
+        if handler:
+            handler()
+        else:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_UNEXPECTED_TOKEN,
+                line=token.line,
+                column=token.column,
+                message=f"'{token.raw}' はここでは使用できません。",
+                severity="error",
+                hint="音符、休符、コマンド、小節線を配置してください。",
+                context=self._context_line(token),
+            )
+            self.ctx.advance()
+
+    def _read_length(self) -> tuple[int, int]:
+        dots = 0
+        length_token = self.ctx.match(TokenType.NUMBER)
+        if length_token is None:
+            length = self.default_length
+        else:
+            length = int(length_token.value)
+        while self.ctx.match(TokenType.DOT):
+            dots += 1
+        return length, dots
+
+    def _parse_note(self) -> None:
+        token = self.ctx.advance()
+        note = token.value.lower()
+        length, dots = self._read_length()
+        ticks = length_value_to_ticks(length, dots)
+        accidental = 0
+        while True:
+            if self.ctx.match(TokenType.SHARP):
+                accidental += 1
+            elif self.ctx.match(TokenType.FLAT):
+                accidental -= 1
+            else:
+                break
+
+        if self.current_channel == "Noise":
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_CHANNEL_MISMATCH,
+                line=token.line,
+                column=token.column,
+                message="チャンネル 'Noise' で音高指定は使用できません。",
+                severity="warning",
+                hint="Noiseチャンネルでは音高ではなく音長と音量のみ指定してください。",
+                context=self._context_line(token),
+            )
+            midi = 0
+        else:
+            midi = note_to_midi(note, self.octave, accidental)
+            if not 0 <= midi <= 127:
+                self.ctx.add_error(
+                    code=ErrorCode.SYNTAX_NOTE_OUT_OF_RANGE,
+                    line=token.line,
+                    column=token.column,
+                    message=f"音高が範囲外です（MIDI音番号 {midi}）。",
+                    severity="warning",
+                    hint="オクターブを調整してください。有効範囲: o0〜o7。",
+                    context=self._context_line(token),
+                )
+                midi = clamp(midi, 0, 127)
+
+        event = NoteEvent(
+            tick_position=self.tick_position,
+            duration=ticks,
+            note_number=midi,
+            velocity=self.velocity,
+            duty=self.duty,
+            gate_time=1.0,
+        )
+        self._add_event(event)
+        self.tick_position += ticks
+
+    def _parse_rest(self) -> None:
+        self.ctx.advance()
+        length, dots = self._read_length()
+        ticks = length_value_to_ticks(length, dots)
+        event = RestEvent(tick_position=self.tick_position, duration=ticks)
+        self._add_event(event)
+        self.tick_position += ticks
+
+    def _parse_octave(self) -> None:
+        token = self.ctx.advance()
+        value = int(token.value)
+        if not 0 <= value <= 7:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'o' の値 {value} は範囲外です。有効範囲: 0〜7。",
+                severity="error",
+                hint="例: o4 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.octave = value
+
+    def _parse_octave_up(self) -> None:
+        self.ctx.advance()
+        if self.octave < 7:
+            self.octave += 1
+
+    def _parse_octave_down(self) -> None:
+        self.ctx.advance()
+        if self.octave > 0:
+            self.octave -= 1
+
+    def _parse_length(self) -> None:
+        token = self.ctx.advance()
+        value = int(token.value)
+        if not 1 <= value <= 192:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'l' の値 {value} は範囲外です。有効範囲: 1〜192。",
+                severity="error",
+                hint="例: l8 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.default_length = value
+
+    def _parse_volume(self) -> None:
+        token = self.ctx.advance()
+        if self.current_channel == "Triangle":
+            # Silently ignored per spec
+            return
+        value = int(token.value)
+        if not 0 <= value <= 15:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'v' の値 {value} は範囲外です。有効範囲: 0〜15。",
+                severity="error",
+                hint="例: v15 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.velocity = value
+
+    def _parse_duty(self) -> None:
+        token = self.ctx.advance()
+        if self.current_channel not in PULSE_CHANNELS:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_CHANNEL_MISMATCH,
+                line=token.line,
+                column=token.column,
+                message=f"チャンネル '{self.current_channel}' で 'q' は使用できません。",
+                severity="warning",
+                hint="Triangleチャンネルはデューティ比を持ちません。q コマンドを削除してください。",
+                context=self._context_line(token),
+            )
+            return
+        value = int(token.value)
+        if not 0 <= value <= 3:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'q' の値 {value} は範囲外です。有効範囲: 0〜3。",
+                severity="error",
+                hint="例: q2 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.duty = value
+        self._add_event(DutyEvent(tick_position=self.tick_position, value=value))
+
+    def _parse_tempo(self) -> None:
+        token = self.ctx.advance()
+        value = int(token.value)
+        if value < 1:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'t' の値 {value} は範囲外です。有効範囲: 1以上。",
+                severity="error",
+                hint="例: t150 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.note_sequence.bpm = value
+        self._add_event(TempoEvent(tick_position=self.tick_position, bpm=value))
+
+    def _parse_tie(self) -> None:
+        token = self.ctx.advance()
+        next_token = self.ctx.peek()
+        if next_token.type not in (TokenType.NOTE, TokenType.REST, TokenType.NUMBER):
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_UNTERMINATED_TIE,
+                line=token.line,
+                column=token.column,
+                message="タイ '&' の後に音符が見つかりません。",
+                severity="error",
+                hint="& の後に音符（例: c4）を続けてください。",
+                context=self._context_line(token),
+            )
+            return
+        if next_token.type == TokenType.NUMBER:
+            self.ctx.advance()
+            ticks = length_value_to_ticks(int(next_token.value), 0)
+            self._extend_last_note(ticks)
+            self.tick_position += ticks
+            return
+        # For note/rest, parser will create next event; we just note that previous
+        # event should be merged. Simple approach: reduce tick_position and mark.
+        # Here we just allow the next note to overwrite position and merge later.
+        # Implementation: back up tick position so next note duration adds to previous.
+        self.tick_position = self._last_note_end()
+
+    def _last_note_end(self) -> int:
+        ch = self.note_sequence.channels[self.current_channel]  # type: ignore[index]
+        for ev in reversed(ch.events):
+            if isinstance(ev, (NoteEvent, RestEvent)):
+                return ev.tick_position
+        return self.tick_position
+
+    def _extend_last_note(self, ticks: int) -> None:
+        ch = self.note_sequence.channels[self.current_channel]  # type: ignore[index]
+        for ev in reversed(ch.events):
+            if isinstance(ev, (NoteEvent, RestEvent)):
+                ev.duration += ticks
+                return
+
+    def _parse_repeat_start(self) -> None:
+        # Stage 2 feature: keep token but do not expand
+        token = self.ctx.advance()
+        self.ctx.add_error(
+            code=ErrorCode.SYNTAX_UNEXPECTED_TOKEN,
+            line=token.line,
+            column=token.column,
+            message="区間リピート '[' は第2段階で実装されます。",
+            severity="warning",
+            hint="現時点では無視されます。",
+            context=self._context_line(token),
+        )
+
+    def _parse_repeat_end(self) -> None:
+        token = self.ctx.advance()
+        self.ctx.add_error(
+            code=ErrorCode.SYNTAX_UNEXPECTED_TOKEN,
+            line=token.line,
+            column=token.column,
+            message="区間リピート ']' は第2段階で実装されます。",
+            severity="warning",
+            hint="現時点では無視されます。",
+            context=self._context_line(token),
+        )
+
+    def _parse_bar(self) -> None:
+        self.ctx.advance()
+
+    def _add_event(self, event) -> None:  # type: ignore[no-untyped-def]
+        ch = self.note_sequence.channels[self.current_channel]  # type: ignore[index]
+        ch.events.append(event)
+
+    def _validate_tracks(self) -> None:
+        for raw, name in CHANNEL_MAP.items():
+            ch = self.note_sequence.channels[name]
+            if name in self.tracks_seen and not ch.events:
+                # Determine approximate line of header (last track header token)
+                header_token = None
+                for tok in self.ctx.tokens:
+                    if tok.type == TokenType.TRACK_HEADER and tok.value.upper() == raw:
+                        header_token = tok
+                self.ctx.add_error(
+                    code=ErrorCode.SYNTAX_EMPTY_TRACK,
+                    line=header_token.line if header_token else 1,
+                    column=header_token.column if header_token else 1,
+                    message=f"トラック '{raw}' に音符または休符がありません。",
+                    severity="error",
+                    hint="少なくとも1つの音符または休符を記述してください。",
+                    context=self._context_line(header_token) if header_token else "",
+                )
+
+
+def parse_ppmck(
+    source: str, tokens: list[Token]
+) -> tuple[NoteSequence, list[ErrorDetail]]:
+    parser = PpmckParser(source, tokens)
+    return parser.parse()
diff --git a/src/mml_composemusic_mcp/parser_pyxel.py b/src/mml_composemusic_mcp/parser_pyxel.py
new file mode 100644
index 0000000..7d3707b
--- /dev/null
+++ b/src/mml_composemusic_mcp/parser_pyxel.py
@@ -0,0 +1,652 @@
+"""Pyxel MML parser."""
+
+from .ir import (
+    DutyEvent,
+    EnvelopeEvent,
+    ErrorCode,
+    ErrorDetail,
+    GlideEvent,
+    NoteEvent,
+    NoteSequence,
+    RepeatEvent,
+    RestEvent,
+    TempoEvent,
+    VibratoEvent,
+    VolumeEvent,
+)
+from .lexer import Token, TokenType
+from .parser_base import (
+    ParserContext,
+    clamp,
+    length_value_to_ticks,
+    note_to_midi,
+)
+
+CHANNEL_MAP = {
+    "0": "Pulse1",
+    "1": "Pulse2",
+    "2": "Triangle",
+    "3": "Noise",
+}
+PULSE_CHANNELS = {"Pulse1", "Pulse2"}
+
+PYXEL_DUTY = {
+    "1": 2,  # Square 50%
+    "2": 1,  # Pulse 25%
+}
+
+
+class PyxelParser:
+    def __init__(self, source: str, tokens: list[Token]) -> None:
+        self.source = source
+        self.ctx = ParserContext(tokens)
+        self.note_sequence = NoteSequence()
+        self.current_channel: str | None = None
+        self.octave = 4
+        self.default_length = 4
+        self.velocity = 100
+        self.gate_time = 0.8
+        self.duty = 2
+        self.transpose = 0
+        self.detune_cents = 0
+        self.tick_position = 0
+        self.tracks_seen: set[str] = set()
+        self.repeat_stack: list[int] = []
+
+    def _context_line(self, token: Token) -> str:
+        lines = self.source.splitlines()
+        if 1 <= token.line <= len(lines):
+            return lines[token.line - 1]
+        return ""
+
+    def parse(self) -> tuple[NoteSequence, list[ErrorDetail]]:
+        while self.ctx.peek().type != TokenType.EOF:
+            token = self.ctx.peek()
+            if token.type == TokenType.TRACK_HEADER:
+                self._parse_track_header()
+                continue
+            if self.current_channel is None:
+                self.ctx.advance()
+                continue
+            self._parse_statement()
+
+        if self.repeat_stack:
+            for _start_tick in self.repeat_stack:
+                self.ctx.add_error(
+                    code=ErrorCode.SYNTAX_UNTERMINATED_REPEAT,
+                    line=1,
+                    column=1,
+                    message="リピート '[' に対応する ']' が見つかりません。",
+                    severity="error",
+                    hint="] を追加してリピートを閉じてください。回数指定（例: ]2）も可能です。",
+                    context="",
+                )
+
+        self._validate_tracks()
+
+        for ch in self.note_sequence.channels.values():
+            ch.total_ticks = max(
+                (e.tick_position + getattr(e, "duration", 0) for e in ch.events),
+                default=0,
+            )
+
+        return self.note_sequence, self.ctx.errors
+
+    def _parse_track_header(self) -> None:
+        token = self.ctx.advance()
+        ch = token.value
+        if ch not in CHANNEL_MAP:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_INVALID_TRACK_HEADER,
+                line=token.line,
+                column=token.column,
+                message=f"無効なトラックヘッダー '{ch}:' です。",
+                severity="error",
+                hint="0:, 1:, 2:, 3: のいずれかを使用してください。",
+                context=self._context_line(token),
+            )
+            self.current_channel = None
+            return
+        self.current_channel = CHANNEL_MAP[ch]
+        if self.current_channel in self.tracks_seen:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_DUPLICATE_TRACK,
+                line=token.line,
+                column=token.column,
+                message=f"トラック '{ch}:' が複数回定義されています。",
+                severity="error",
+                hint="各トラックは1回のみ定義できます。重複定義を削除してください。",
+                context=self._context_line(token),
+            )
+        self.tracks_seen.add(self.current_channel)
+        self.octave = 4
+        self.default_length = 4
+        self.velocity = 100
+        self.gate_time = 0.8
+        self.duty = 2
+        self.transpose = 0
+        self.detune_cents = 0
+        self.tick_position = 0
+
+    def _parse_statement(self) -> None:
+        token = self.ctx.peek()
+        handlers = {
+            TokenType.NOTE: self._parse_note,
+            TokenType.REST: self._parse_rest,
+            TokenType.OCTAVE: self._parse_octave,
+            TokenType.OCTAVE_UP: self._parse_octave_up,
+            TokenType.OCTAVE_DOWN: self._parse_octave_down,
+            TokenType.LENGTH: self._parse_length,
+            TokenType.VOLUME: self._parse_volume,
+            TokenType.GATE_TIME: self._parse_gate_time,
+            TokenType.DUTY: self._parse_duty,
+            TokenType.AT: self._parse_at,
+            TokenType.TEMPO: self._parse_tempo,
+            TokenType.TRANSPOSE: self._parse_transpose,
+            TokenType.DETUNE: self._parse_detune,
+            TokenType.TIE: self._parse_tie,
+            TokenType.REPEAT_START: self._parse_repeat_start,
+            TokenType.REPEAT_END: self._parse_repeat_end,
+            TokenType.EXT_CMD: self._parse_ext_cmd,
+            TokenType.BAR: self._parse_bar,
+        }
+        handler = handlers.get(token.type)
+        if handler:
+            handler()
+        else:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_UNEXPECTED_TOKEN,
+                line=token.line,
+                column=token.column,
+                message=f"'{token.raw}' はここでは使用できません。",
+                severity="error",
+                hint="音符、休符、コマンド、小節線を配置してください。",
+                context=self._context_line(token),
+            )
+            self.ctx.advance()
+
+    def _read_length(self) -> tuple[int, int]:
+        dots = 0
+        length_token = self.ctx.match(TokenType.NUMBER)
+        if length_token is None:
+            length = self.default_length
+        else:
+            length = int(length_token.value)
+        while self.ctx.match(TokenType.DOT):
+            dots += 1
+        return length, dots
+
+    def _parse_note(self) -> None:
+        token = self.ctx.advance()
+        note = token.value.lower()
+        length, dots = self._read_length()
+        ticks = length_value_to_ticks(length, dots)
+        accidental = 0
+        while True:
+            if self.ctx.match(TokenType.SHARP):
+                accidental += 1
+            elif self.ctx.match(TokenType.FLAT):
+                accidental -= 1
+            else:
+                break
+
+        if self.current_channel == "Noise":
+            midi = note_to_midi(note, self.octave, accidental)
+        else:
+            midi = note_to_midi(note, self.octave, accidental) + self.transpose
+            if not 0 <= midi <= 127:
+                self.ctx.add_error(
+                    code=ErrorCode.SYNTAX_NOTE_OUT_OF_RANGE,
+                    line=token.line,
+                    column=token.column,
+                    message=f"音高が範囲外です（MIDI音番号 {midi}）。",
+                    severity="warning",
+                    hint="オクターブ/トランスポーズを調整してください。有効範囲: O0〜O7。",
+                    context=self._context_line(token),
+                )
+                midi = clamp(midi, 0, 127)
+
+        event = NoteEvent(
+            tick_position=self.tick_position,
+            duration=ticks,
+            note_number=midi,
+            velocity=self._normalize_velocity(self.velocity),
+            duty=self.duty,
+            gate_time=self.gate_time,
+        )
+        self._add_event(event)
+        self.tick_position += ticks
+
+    def _parse_rest(self) -> None:
+        self.ctx.advance()
+        length, dots = self._read_length()
+        ticks = length_value_to_ticks(length, dots)
+        event = RestEvent(tick_position=self.tick_position, duration=ticks)
+        self._add_event(event)
+        self.tick_position += ticks
+
+    def _parse_octave(self) -> None:
+        token = self.ctx.advance()
+        value = int(token.value)
+        if not -1 <= value <= 9:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'O' の値 {value} は範囲外です。有効範囲: -1〜9。",
+                severity="error",
+                hint="例: O4 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.octave = value
+
+    def _parse_octave_up(self) -> None:
+        self.ctx.advance()
+        if self.octave < 9:
+            self.octave += 1
+
+    def _parse_octave_down(self) -> None:
+        self.ctx.advance()
+        if self.octave > -1:
+            self.octave -= 1
+
+    def _parse_length(self) -> None:
+        token = self.ctx.advance()
+        value = int(token.value)
+        if not 1 <= value <= 192:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'L' の値 {value} は範囲外です。有効範囲: 1〜192。",
+                severity="error",
+                hint="例: L8 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.default_length = value
+
+    def _parse_volume(self) -> None:
+        token = self.ctx.advance()
+        value = int(token.value)
+        if not 0 <= value <= 127:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'V' の値 {value} は範囲外です。有効範囲: 0〜127。",
+                severity="error",
+                hint="例: V100 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.velocity = value
+        self._add_event(
+            VolumeEvent(
+                tick_position=self.tick_position,
+                value=self._normalize_velocity(value),
+            )
+        )
+
+    def _normalize_velocity(self, value: int) -> int:
+        return round(value / 127 * 15)
+
+    def _parse_gate_time(self) -> None:
+        token = self.ctx.advance()
+        value = int(token.value)
+        if not 0 <= value <= 100:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'Q' の値 {value} は範囲外です。有効範囲: 0〜100。",
+                severity="error",
+                hint="例: Q80 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.gate_time = value / 100.0
+
+    def _parse_duty(self, cmd_raw: str = "Q") -> None:
+        # Q command maps to duty per Design_mml legacy section
+        token = self.ctx.peek()
+        value = int(token.value)
+        if not 0 <= value <= 3:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'{cmd_raw}' の値 {value} は範囲外です。有効範囲: 0〜3。",
+                severity="error",
+                hint=f"例: {cmd_raw}2 のように指定してください。",
+                context=self._context_line(token),
+            )
+            self.ctx.advance()
+            return
+        if self.current_channel not in PULSE_CHANNELS:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_CHANNEL_MISMATCH,
+                line=token.line,
+                column=token.column,
+                message=f"チャンネル '{self.current_channel}' で '{cmd_raw}' は使用できません。",
+                severity="warning",
+                hint=f"{self.current_channel}チャンネルではデューティ比を持ちません。{cmd_raw} コマンドを削除してください。",
+                context=self._context_line(token),
+            )
+            self.ctx.advance()
+            return
+        self.duty = value
+        self._add_event(DutyEvent(tick_position=self.tick_position, value=value))
+        self.ctx.advance()
+
+    def _parse_at(self) -> None:
+        token = self.ctx.advance()
+        value = token.value
+        if value in PYXEL_DUTY:
+            if self.current_channel not in PULSE_CHANNELS:
+                self.ctx.add_error(
+                    code=ErrorCode.SYNTAX_CHANNEL_MISMATCH,
+                    line=token.line,
+                    column=token.column,
+                    message=f"チャンネル '{self.current_channel}' で '@{value}' は使用できません。",
+                    severity="warning",
+                    hint="トラック番号がチャンネルを決定します。@ コマンドを削除するか、Pulseチャンネル（0: または 1:）に移動してください。",
+                    context=self._context_line(token),
+                )
+                return
+            self.duty = PYXEL_DUTY[value]
+            self._add_event(
+                DutyEvent(tick_position=self.tick_position, value=self.duty)
+            )
+            return
+        if value == "0":
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_CHANNEL_MISMATCH,
+                line=token.line,
+                column=token.column,
+                message=f"チャンネル '{self.current_channel}' で '@0' (Triangle) は使用できません。",
+                severity="warning",
+                hint="トラック番号がチャンネルを決定します。@ コマンドを削除するか、適切なチャンネルに移動してください。",
+                context=self._context_line(token),
+            )
+        elif value == "3":
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_CHANNEL_MISMATCH,
+                line=token.line,
+                column=token.column,
+                message=f"チャンネル '{self.current_channel}' で '@3' (Noise) は使用できません。",
+                severity="warning",
+                hint="トラック番号がチャンネルを決定します。@ コマンドを削除するか、適切なチャンネルに移動してください。",
+                context=self._context_line(token),
+            )
+        else:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_INVALID_NUMBER,
+                line=token.line,
+                column=token.column,
+                message=f"'@' の後に無効な値 '{value}' が見つかりました。",
+                severity="error",
+                hint="例: @1 のように指定してください。",
+                context=self._context_line(token),
+            )
+
+    def _parse_tempo(self) -> None:
+        token = self.ctx.advance()
+        value = int(token.value)
+        if value < 1:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_VALUE_OUT_OF_RANGE,
+                line=token.line,
+                column=token.column,
+                message=f"'T' の値 {value} は範囲外です。有効範囲: 1以上。",
+                severity="error",
+                hint="例: T150 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        self.note_sequence.bpm = value
+        self._add_event(TempoEvent(tick_position=self.tick_position, bpm=value))
+
+    def _parse_transpose(self) -> None:
+        token = self.ctx.advance()
+        self.transpose = int(token.value)
+
+    def _parse_detune(self) -> None:
+        token = self.ctx.advance()
+        self.detune_cents = int(token.value)
+
+    def _parse_tie(self) -> None:
+        token = self.ctx.advance()
+        next_token = self.ctx.peek()
+        if next_token.type not in (TokenType.NOTE, TokenType.REST, TokenType.NUMBER):
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_UNTERMINATED_TIE,
+                line=token.line,
+                column=token.column,
+                message="タイ '&' の後に音符が見つかりません。",
+                severity="error",
+                hint="& の後に音符（例: C4）を続けてください。音長のみ（例: &16）も可能です。",
+                context=self._context_line(token),
+            )
+            return
+        if next_token.type == TokenType.NUMBER:
+            self.ctx.advance()
+            ticks = length_value_to_ticks(int(next_token.value), 0)
+            self._extend_last_note(ticks)
+            self.tick_position += ticks
+            return
+        self.tick_position = self._last_note_end()
+
+    def _last_note_end(self) -> int:
+        ch = self.note_sequence.channels[self.current_channel]  # type: ignore[index]
+        for ev in reversed(ch.events):
+            if isinstance(ev, (NoteEvent, RestEvent)):
+                return ev.tick_position
+        return self.tick_position
+
+    def _extend_last_note(self, ticks: int) -> None:
+        ch = self.note_sequence.channels[self.current_channel]  # type: ignore[index]
+        for ev in reversed(ch.events):
+            if isinstance(ev, (NoteEvent, RestEvent)):
+                ev.duration += ticks
+                return
+
+    def _parse_repeat_start(self) -> None:
+        self.ctx.advance()
+        self.repeat_stack.append(self.tick_position)
+
+    def _parse_repeat_end(self) -> None:
+        token = self.ctx.advance()
+        if not self.repeat_stack:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_UNMATCHED_REPEAT_END,
+                line=token.line,
+                column=token.column,
+                message="']' に対応する '[' が見つかりません。",
+                severity="error",
+                hint="直前の [ を確認するか、余分な ] を削除してください。",
+                context=self._context_line(token),
+            )
+            return
+        start_tick = self.repeat_stack.pop()
+        count_str = token.value
+        if count_str == "":
+            count = 0  # infinite
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_UNEXPECTED_TOKEN,
+                line=token.line,
+                column=token.column,
+                message="無限リピートはWAV生成時に2回で打ち切られます。",
+                severity="warning",
+                hint="回数を指定するか、2回の再生で十分であることを確認してください。",
+                context=self._context_line(token),
+            )
+        else:
+            count = int(count_str)
+        segment = [
+            e
+            for e in self.note_sequence.channels[self.current_channel].events  # type: ignore[index]
+            if start_tick <= e.tick_position < self.tick_position
+        ]
+        repeat_count = 2 if count == 0 else count
+        for i in range(1, repeat_count):
+            offset = i * (self.tick_position - start_tick)
+            for ev in segment:
+                new_event = self._clone_event(ev, ev.tick_position + offset)
+                self._add_event(new_event)
+                if isinstance(new_event, (NoteEvent, RestEvent)):
+                    end = new_event.tick_position + new_event.duration
+                    if end > self.tick_position:
+                        self.tick_position = end
+        self.note_sequence.channels[self.current_channel].events.sort(  # type: ignore[index]
+            key=lambda e: e.tick_position
+        )
+        self._add_event(
+            RepeatEvent(
+                start_tick=start_tick,
+                end_tick=self.tick_position,
+                repeat_count=count,
+            )
+        )
+
+    def _clone_event(self, event, tick_position: int):  # type: ignore[no-untyped-def]
+        import copy
+
+        new = copy.copy(event)
+        new.tick_position = tick_position
+        return new
+
+    def _parse_ext_cmd(self) -> None:
+        token = self.ctx.advance()
+        cmd = token.value  # ENV, VIB, GLI
+        slot_token = self.ctx.match(TokenType.NUMBER)
+        if slot_token is None:
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_INVALID_NUMBER,
+                line=token.line,
+                column=token.column,
+                message=f"'@{cmd}' の後にスロット番号が必要です。",
+                severity="error",
+                hint=f"例: @{cmd}1 のように指定してください。",
+                context=self._context_line(token),
+            )
+            return
+        slot = int(slot_token.value)
+        if slot == 0:
+            # OFF
+            if cmd == "ENV":
+                ev = EnvelopeEvent(tick_position=self.tick_position, slot=0)
+            elif cmd == "VIB":
+                ev = VibratoEvent(tick_position=self.tick_position, slot=0)
+            else:
+                ev = GlideEvent(tick_position=self.tick_position, slot=0)
+            self._add_event(ev)
+            return
+        if self.ctx.match(TokenType.NUMBER):
+            # definition without braces; simplistic parse numbers until non-number
+            # Real Pyxel uses { ... }; we accept a flat sequence of ints for now.
+            values = [int(slot_token.value)]
+            while True:
+                num = self.ctx.match(TokenType.NUMBER)
+                if num is None:
+                    break
+                values.append(int(num.value))
+            if cmd == "ENV":
+                points = []
+                for i in range(1, len(values), 2):
+                    duration = values[i]
+                    target = values[i - 1] if i - 1 < len(values) else values[-1]
+                    points.append({"target_volume": target, "duration_ticks": duration})
+                ev = EnvelopeEvent(
+                    tick_position=self.tick_position,
+                    slot=slot,
+                    points=points,
+                )
+            elif cmd == "VIB":
+                if len(values) >= 3:
+                    params = {
+                        "delay_ticks": values[0],
+                        "period_ticks": values[1],
+                        "depth_cents": values[2],
+                    }
+                else:
+                    params = {}
+                ev = VibratoEvent(
+                    tick_position=self.tick_position,
+                    slot=slot,
+                    params=params,
+                )
+            else:
+                if len(values) >= 2:
+                    params = {
+                        "initial_offset_cents": values[0],
+                        "duration_ticks": values[1],
+                    }
+                else:
+                    params = {}
+                ev = GlideEvent(
+                    tick_position=self.tick_position,
+                    slot=slot,
+                    params=params,
+                )
+            self._add_event(ev)
+            self.ctx.add_error(
+                code=ErrorCode.SYNTAX_UNEXPECTED_TOKEN,
+                line=token.line,
+                column=token.column,
+                message=f"@{cmd} は第1段階では未サポート、無視されます。",
+                severity="warning",
+                hint="合成には反映されませんが、IRとして保持されます。",
+                context=self._context_line(token),
+            )
+            return
+        # Slot switch only
+        if cmd == "ENV":
+            ev = EnvelopeEvent(tick_position=self.tick_position, slot=slot)
+        elif cmd == "VIB":
+            ev = VibratoEvent(tick_position=self.tick_position, slot=slot)
+        else:
+            ev = GlideEvent(tick_position=self.tick_position, slot=slot)
+        self._add_event(ev)
+        self.ctx.add_error(
+            code=ErrorCode.SYNTAX_UNEXPECTED_TOKEN,
+            line=token.line,
+            column=token.column,
+            message=f"@{cmd} は第1段階では未サポート、無視されます。",
+            severity="warning",
+            hint="合成には反映されませんが、IRとして保持されます。",
+            context=self._context_line(token),
+        )
+
+    def _parse_bar(self) -> None:
+        self.ctx.advance()
+
+    def _add_event(self, event) -> None:  # type: ignore[no-untyped-def]
+        ch = self.note_sequence.channels[self.current_channel]  # type: ignore[index]
+        ch.events.append(event)
+
+    def _validate_tracks(self) -> None:
+        for raw, name in CHANNEL_MAP.items():
+            ch = self.note_sequence.channels[name]
+            if name in self.tracks_seen and not ch.events:
+                header_token = None
+                for tok in self.ctx.tokens:
+                    if tok.type == TokenType.TRACK_HEADER and tok.value == raw:
+                        header_token = tok
+                self.ctx.add_error(
+                    code=ErrorCode.SYNTAX_EMPTY_TRACK,
+                    line=header_token.line if header_token else 1,
+                    column=header_token.column if header_token else 1,
+                    message=f"トラック '{raw}:' に音符または休符がありません。",
+                    severity="error",
+                    hint="少なくとも1つの音符または休符を記述してください。",
+                    context=self._context_line(header_token) if header_token else "",
+                )
+
+
+def parse_pyxel(
+    source: str, tokens: list[Token]
+) -> tuple[NoteSequence, list[ErrorDetail]]:
+    parser = PyxelParser(source, tokens)
+    return parser.parse()
diff --git a/src/mml_composemusic_mcp/server.py b/src/mml_composemusic_mcp/server.py
new file mode 100644
index 0000000..1205b70
--- /dev/null
+++ b/src/mml_composemusic_mcp/server.py
@@ -0,0 +1,254 @@
+# MCP server exposing compose_mml tool.
+
+import argparse
+from pathlib import Path
+
+from fastmcp import FastMCP
+
+from .ir import ErrorCode, ErrorDetail, NoteSequence
+from .lexer import tokenize
+from .parser_ppmck import parse_ppmck
+from .parser_pyxel import parse_pyxel
+from .synthesizer import build_channel_summary, synthesize, write_wav
+from .templates import get_template
+
+mcp = FastMCP("mml-composemusic-mcp")
+OUTPUT_DIR = Path("./data")
+
+
+def _is_error(errors: list[ErrorDetail]) -> bool:
+    return any(e.severity == "error" for e in errors)
+
+
+def _split_errors(errors: list[ErrorDetail]) -> tuple[list[dict], list[dict]]:
+    errs = [e.to_dict() for e in errors if e.severity == "error"]
+    warns = [e.to_dict() for e in errors if e.severity == "warning"]
+    return errs, warns
+
+
+def _parse_mml(mml: str, mode: str) -> tuple[dict, list[ErrorDetail]]:
+    tokens = tokenize(mml, mode)
+    if mode == "ppmck":
+        note_sequence, errors = parse_ppmck(mml, tokens)
+    elif mode == "pyxel":
+        note_sequence, errors = parse_pyxel(mml, tokens)
+    else:
+        errors = [
+            ErrorDetail(
+                code=ErrorCode.SYNTAX_INVALID_TOKEN,
+                line=0,
+                column=0,
+                message=f"未知のモード '{mode}' です。",
+                severity="error",
+                hint="mode は 'ppmck' または 'pyxel' を指定してください。",
+            )
+        ]
+        note_sequence = None
+    return (note_sequence.to_dict() if note_sequence else None), errors
+
+
+@mcp.tool()
+def compose_mml(
+    action: str,
+    mml: str = "",
+    mode: str = "",
+    template: str = "basic",
+    sample_rate: int = 44100,
+    normalize: bool = True,
+) -> dict:
+    """Compose, validate, or generate templates for Famicom-style MML."""
+    if action == "template":
+        if mode not in ("ppmck", "pyxel"):
+            mode = "ppmck"
+        if template not in ("basic", "melody", "chord", "drum", "empty"):
+            template = "basic"
+        mml_text, description = get_template(mode, template)
+        return {"mml": mml_text, "description": description}
+
+    if action in ("compose", "validate"):
+        if not mml or not mode:
+            return {
+                "success": False,
+                "valid": False,
+                "errors": [
+                    {
+                        "code": ErrorCode.SYNTAX_INVALID_TOKEN.value,
+                        "line": 0,
+                        "column": 0,
+                        "message": "mml と mode は compose/validate の必須パラメータです。",
+                        "severity": "error",
+                        "hint": "mml に MML 文字列、mode に 'ppmck' または 'pyxel' を指定してください。",
+                    }
+                ],
+                "warnings": [],
+            }
+        note_sequence_dict, errors = _parse_mml(mml, mode)
+        errors_list, warnings_list = _split_errors(errors)
+        if action == "validate":
+            return {
+                "valid": not _is_error(errors),
+                "errors": errors_list,
+                "note_sequence": note_sequence_dict,
+                "channel_summary": build_channel_summary(note_sequence_dict)
+                if note_sequence_dict
+                else [],
+            }
+        # compose
+        if _is_error(errors):
+            return {
+                "success": False,
+                "wav_path": None,
+                "duration_sec": 0,
+                "note_sequence": note_sequence_dict,
+                "validation": {"errors": errors_list, "warnings": warnings_list},
+            }
+
+        ns = _dict_to_note_sequence(note_sequence_dict)
+        try:
+            wave_data, duration, synth_errors = synthesize(
+                ns, mode, sample_rate, normalize
+            )
+        except Exception as exc:
+            return {
+                "success": False,
+                "wav_path": None,
+                "duration_sec": 0,
+                "note_sequence": note_sequence_dict,
+                "validation": {
+                    "errors": [
+                        {
+                            "code": ErrorCode.SYSTEM_SYNTHESIS_FAILED.value,
+                            "line": 0,
+                            "column": 0,
+                            "message": f"音声合成中にエラーが発生しました: {exc}",
+                            "severity": "error",
+                            "hint": "MMLの内容を確認の上、再度お試しください。問題が続く場合は、短いMMLから試してください。",
+                        }
+                    ],
+                    "warnings": warnings_list,
+                },
+            }
+        errors.extend(synth_errors)
+        errors_list, warnings_list = _split_errors(errors)
+        if _is_error(errors):
+            return {
+                "success": False,
+                "wav_path": None,
+                "duration_sec": 0,
+                "note_sequence": note_sequence_dict,
+                "validation": {"errors": errors_list, "warnings": warnings_list},
+            }
+        wav_path = OUTPUT_DIR / "output.wav"
+        wav_errors = write_wav(wav_path, wave_data, sample_rate)
+        errors.extend(wav_errors)
+        errors_list, warnings_list = _split_errors(errors)
+        return {
+            "success": not _is_error(errors),
+            "wav_path": str(wav_path) if not _is_error(errors) else None,
+            "duration_sec": duration,
+            "note_sequence": note_sequence_dict,
+            "validation": {"errors": errors_list, "warnings": warnings_list},
+        }
+
+    return {
+        "success": False,
+        "errors": [
+            {
+                "code": ErrorCode.SYNTAX_INVALID_TOKEN.value,
+                "line": 0,
+                "column": 0,
+                "message": f"未知の action '{action}' です。",
+                "severity": "error",
+                "hint": "action は 'compose', 'validate', 'template' のいずれかを指定してください。",
+            }
+        ],
+        "warnings": [],
+    }
+
+
+def _dict_to_note_sequence(data: dict) -> NoteSequence:
+    from .ir import (
+        ChannelSequence,
+        DutyEvent,
+        EnvelopeEvent,
+        GlideEvent,
+        NoteEvent,
+        NoteSequence,
+        RepeatEvent,
+        RestEvent,
+        TempoEvent,
+        VibratoEvent,
+        VolumeEvent,
+    )
+
+    ns = NoteSequence(
+        version=data["version"],
+        bpm=data["bpm"],
+        ticks_per_quarter=data["ticks_per_quarter"],
+        channels={},
+    )
+    for name, ch_data in data["channels"].items():
+        ch = ChannelSequence(
+            channel_type=ch_data["channel_type"],
+            events=[],
+            total_ticks=ch_data["total_ticks"],
+        )
+        for ev in ch_data["events"]:
+            ev_type = ev["type"]
+            if ev_type == "note":
+                ch.events.append(NoteEvent(**ev))
+            elif ev_type == "rest":
+                ch.events.append(RestEvent(**ev))
+            elif ev_type == "volume":
+                ch.events.append(VolumeEvent(**ev))
+            elif ev_type == "duty":
+                ch.events.append(DutyEvent(**ev))
+            elif ev_type == "tempo":
+                ch.events.append(TempoEvent(**ev))
+            elif ev_type == "repeat":
+                ch.events.append(RepeatEvent(**ev))
+            elif ev_type == "envelope":
+                ch.events.append(EnvelopeEvent(**ev))
+            elif ev_type == "vibrato":
+                ch.events.append(VibratoEvent(**ev))
+            elif ev_type == "glide":
+                ch.events.append(GlideEvent(**ev))
+        ns.channels[name] = ch
+    return ns
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description="MML Compose MCP Server")
+    parser.add_argument(
+        "--output-dir",
+        type=str,
+        default="./data",
+        help="Directory to store generated WAV files (default: ./data)",
+    )
+    parser.add_argument(
+        "--transport",
+        type=str,
+        default="stdio",
+        choices=["stdio", "http", "sse", "streamable-http"],
+        help="MCP transport (default: stdio)",
+    )
+    parser.add_argument(
+        "--host",
+        type=str,
+        default="127.0.0.1",
+        help="Host to bind for HTTP-based transports (default: 127.0.0.1)",
+    )
+    parser.add_argument(
+        "--port",
+        type=int,
+        default=8080,
+        help="Port to bind for HTTP-based transports (default: 8080)",
+    )
+    args = parser.parse_args()
+    global OUTPUT_DIR
+    OUTPUT_DIR = Path(args.output_dir)
+    mcp.run(transport=args.transport, host=args.host, port=args.port)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/src/mml_composemusic_mcp/synthesizer.py b/src/mml_composemusic_mcp/synthesizer.py
new file mode 100644
index 0000000..42a3c11
--- /dev/null
+++ b/src/mml_composemusic_mcp/synthesizer.py
@@ -0,0 +1,301 @@
+"""NES APU-style synthesizer: NoteSequence -> WAV."""
+
+import wave
+from math import floor
+from pathlib import Path
+
+import numpy as np
+
+from .ir import (
+    DutyEvent,
+    ErrorCode,
+    ErrorDetail,
+    NoteEvent,
+    NoteSequence,
+    RestEvent,
+    TempoEvent,
+    VolumeEvent,
+)
+
+CPU_CLOCK = 1_789_772.5
+SAMPLE_RATE_DEFAULT = 44100
+
+
+def midi_to_freq(note_number: int) -> float:
+    return 440.0 * 2.0 ** ((note_number - 69) / 12.0)
+
+
+def noise_period_to_rate(period: int, mode: int, sample_rate: int) -> float:
+    # NES noise: rate = CPU_CLOCK / (NTSC divider for period)
+    # Approximate using pyxel mapping described in design
+    dividers = [
+        4,
+        8,
+        16,
+        32,
+        64,
+        96,
+        128,
+        160,
+        202,
+        254,
+        380,
+        508,
+        762,
+        1016,
+        2034,
+        4068,
+    ]
+    div = dividers[period & 0x0F]
+    # Long mode (0) vs short mode (1) affects LFSR length, not frequency divider
+    return CPU_CLOCK / div
+
+
+class ChannelSynthesizer:
+    def __init__(
+        self, channel_type: str, sample_rate: int = SAMPLE_RATE_DEFAULT
+    ) -> None:
+        self.channel_type = channel_type
+        self.sample_rate = sample_rate
+        self.wave = np.zeros(0, dtype=np.float64)
+
+    def render(
+        self,
+        events: list,
+        total_ticks: int,
+        bpm: int,
+        mode: str,
+    ) -> np.ndarray:
+        seconds = tick_to_second(total_ticks, bpm)
+        length = int(seconds * self.sample_rate)
+        self.wave = np.zeros(length, dtype=np.float64)
+        last_velocity = 15 if self.channel_type != "triangle" else 15
+        last_duty = 2
+        for event in events:
+            if isinstance(event, VolumeEvent):
+                last_velocity = event.value
+                continue
+            if isinstance(event, DutyEvent):
+                last_duty = event.value
+                continue
+            if isinstance(event, TempoEvent):
+                bpm = event.bpm
+                continue
+            if not isinstance(event, (NoteEvent, RestEvent)):
+                continue
+            start_sample = int(
+                tick_to_second(event.tick_position, bpm) * self.sample_rate
+            )
+            end_tick = event.tick_position + event.duration
+            end_sample = min(
+                int(tick_to_second(end_tick, bpm) * self.sample_rate), length
+            )
+            if start_sample >= length or end_sample <= start_sample:
+                continue
+            if isinstance(event, RestEvent):
+                continue
+            self._render_note(
+                start_sample,
+                end_sample,
+                event,
+                last_velocity,
+                last_duty,
+                mode,
+            )
+        return self.wave
+
+    def _render_note(
+        self,
+        start: int,
+        end: int,
+        event: NoteEvent,
+        velocity: int,
+        duty: int,
+        mode: str,
+    ) -> None:
+        duration_samples = end - start
+        if duration_samples <= 0:
+            return
+        if self.channel_type == "noise":
+            self._render_noise(start, end, event, velocity, mode)
+            return
+        if self.channel_type == "triangle":
+            self._render_triangle(start, end, event, velocity, mode)
+            return
+        self._render_pulse(start, end, event, velocity, duty)
+
+    def _render_pulse(
+        self,
+        start: int,
+        end: int,
+        event: NoteEvent,
+        velocity: int,
+        duty: int,
+    ) -> None:
+        freq = midi_to_freq(event.note_number)
+        if freq <= 0:
+            return
+        phase_inc = freq / self.sample_rate
+        duty_cycle = {0: 0.125, 1: 0.25, 2: 0.5, 3: 0.75}.get(duty, 0.5)
+        samples = np.arange(end - start)
+        phase = (samples * phase_inc) % 1.0
+        waveform = np.where(phase < duty_cycle, 1.0, -1.0)
+        amp = velocity / 15.0
+        gate = max(0.0, min(1.0, event.gate_time))
+        if gate < 1.0:
+            gate_sample = int((end - start) * gate)
+            if gate_sample < len(waveform):
+                waveform[gate_sample:] = 0.0
+        self.wave[start:end] += waveform * amp
+
+    def _render_triangle(
+        self,
+        start: int,
+        end: int,
+        event: NoteEvent,
+        velocity: int,
+        mode: str,
+    ) -> None:
+        freq = midi_to_freq(event.note_number)
+        if freq <= 0:
+            return
+        phase_inc = freq / self.sample_rate
+        samples = np.arange(end - start)
+        phase = (samples * phase_inc) % 1.0
+        # 32-step triangle approximated by abs(phase*2-1)
+        waveform = 2.0 * np.abs(phase * 2.0 - 1.0) - 1.0
+        if mode == "pyxel":
+            amp = velocity / 15.0
+        else:
+            amp = 1.0
+        gate = max(0.0, min(1.0, event.gate_time))
+        if gate < 1.0:
+            gate_sample = int((end - start) * gate)
+            if gate_sample < len(waveform):
+                waveform[gate_sample:] = 0.0
+        self.wave[start:end] += waveform * amp
+
+    def _render_noise(
+        self,
+        start: int,
+        end: int,
+        event: NoteEvent,
+        velocity: int,
+        mode: str,
+    ) -> None:
+        if mode == "pyxel":
+            period = max(0, min(15, 15 - floor(event.note_number / 8)))
+            mode_flag = 1 if period >= 13 else 0
+        else:
+            period = 8
+            mode_flag = 0
+        rate = noise_period_to_rate(period, mode_flag, self.sample_rate)
+        phase_inc = rate / self.sample_rate
+        samples = np.arange(end - start)
+        phase = (samples * phase_inc) % 1.0
+        diff = np.diff(phase, prepend=0)
+        transitions = diff < 0
+        # LFSR-like pseudo-random toggling on each period rollover
+        state = np.zeros(len(samples), dtype=np.int32)
+        lfsr = 1
+        for i in range(len(samples)):
+            if transitions[i]:
+                # feedback bit
+                if mode_flag:
+                    bit = (lfsr ^ (lfsr >> 6)) & 1
+                    lfsr = ((lfsr >> 1) | (bit << 14)) & 0x7FFF
+                else:
+                    bit = (lfsr ^ (lfsr >> 1)) & 1
+                    lfsr = ((lfsr >> 1) | (bit << 14)) & 0x7FFF
+            state[i] = lfsr & 1
+        waveform = np.where(state, 1.0, -1.0)
+        amp = velocity / 15.0
+        gate = max(0.0, min(1.0, event.gate_time))
+        if gate < 1.0:
+            gate_sample = int((end - start) * gate)
+            if gate_sample < len(waveform):
+                waveform[gate_sample:] = 0.0
+        self.wave[start:end] += waveform * amp
+
+
+def tick_to_second(tick: int, bpm: int, ticks_per_quarter: int = 192) -> float:
+    quarter_seconds = 60.0 / bpm
+    return tick * (quarter_seconds / ticks_per_quarter)
+
+
+def synthesize(
+    note_sequence: NoteSequence,
+    mode: str,
+    sample_rate: int = SAMPLE_RATE_DEFAULT,
+    normalize: bool = True,
+) -> tuple[np.ndarray, float, list[ErrorDetail]]:
+    errors: list[ErrorDetail] = []
+    total_ticks = max(ch.total_ticks for ch in note_sequence.channels.values())
+    if total_ticks <= 0:
+        return np.zeros(0, dtype=np.float64), 0.0, errors
+    channels = []
+    for _name, ch in note_sequence.channels.items():
+        synth = ChannelSynthesizer(ch.channel_type, sample_rate)
+        wave = synth.render(ch.events, total_ticks, note_sequence.bpm, mode)
+        channels.append(wave)
+    max_len = max(len(w) for w in channels)
+    padded = [np.pad(w, (0, max_len - len(w)), mode="constant") for w in channels]
+    mixed = np.mean(padded, axis=0)
+    peak = np.max(np.abs(mixed))
+    if normalize and peak > 0:
+        mixed = mixed / peak
+    mixed = np.clip(mixed, -1.0, 1.0)
+    duration = max_len / sample_rate
+    return mixed, duration, errors
+
+
+def write_wav(path: Path, wave_data: np.ndarray, sample_rate: int) -> list[ErrorDetail]:
+    errors: list[ErrorDetail] = []
+    try:
+        path.parent.mkdir(parents=True, exist_ok=True)
+        pcm = np.int16(np.clip(wave_data * 32767, -32768, 32767))
+        with wave.open(str(path), "wb") as wav:
+            wav.setnchannels(1)
+            wav.setsampwidth(2)
+            wav.setframerate(sample_rate)
+            wav.writeframes(pcm.tobytes())
+    except Exception as exc:
+        errors.append(
+            ErrorDetail(
+                code=ErrorCode.SYSTEM_WAV_WRITE_FAILED,
+                line=0,
+                column=0,
+                message=f"WAVファイルの出力に失敗しました: {exc}",
+                severity="error",
+                hint="しばらく待ってから再度お試しください。",
+            )
+        )
+    return errors
+
+
+def build_channel_summary(note_sequence: NoteSequence | dict) -> list[dict]:
+    if isinstance(note_sequence, dict):
+        channels = note_sequence["channels"]
+    else:
+        channels = note_sequence.channels
+    summary = []
+    for name, ch in channels.items():
+        events = ch["events"] if isinstance(ch, dict) else ch.events
+        total_ticks = ch["total_ticks"] if isinstance(ch, dict) else ch.total_ticks
+        notes = [e for e in events if isinstance(e, NoteEvent)]
+        if not notes:
+            notes = [
+                e for e in events if isinstance(e, dict) and e.get("type") == "note"
+            ]
+            octaves = [e["note_number"] // 12 - 1 for e in notes]
+        else:
+            octaves = [e.note_number // 12 - 1 for e in notes]
+        summary.append(
+            {
+                "channel": name,
+                "note_count": len(notes),
+                "octave_range": [min(octaves, default=4), max(octaves, default=4)],
+                "duration_ticks": total_ticks,
+            }
+        )
+    return summary
diff --git a/src/mml_composemusic_mcp/templates.py b/src/mml_composemusic_mcp/templates.py
new file mode 100644
index 0000000..f351583
--- /dev/null
+++ b/src/mml_composemusic_mcp/templates.py
@@ -0,0 +1,32 @@
+# MML template generators for both modes.
+
+TEMPLATES = {
+    "ppmck": {
+        "basic": '#TITLE "Basic Song"\n#COMPOSER "LLM"\n\nA t120 l8 o4 v15 q2\n  c d e f | g a b > c\n\nB l8 o3 v12 q1\n  e g b r | e g b r\n\nT l4 o3 v7\n  c2 g2 e2 c2\n\nN l8 v10\n  c r c r | c r c r\n',
+        "melody": '#TITLE "Melody Lead"\n#COMPOSER "LLM"\n\nA t120 l8 o5 v15 q2\n  c e g e | d f a f | e g b g | c4 r4\n\nB l8 o4 v10 q1\n  c e g e | c e g e | d f a f | c4 r4\n\nT l4 o3 v7\n  c2 g2 | a2 f2 | g2 d2 | c2 r2\n\nN l8 v8\n  c r c r | c r c r | c r c r | c r c r\n',
+        "chord": '#TITLE "Chord Backing"\n#COMPOSER "LLM"\n\nA t120 l4 o4 v12 q2\n  c e g c | f a > c f | g b > d g | c e g c\n\nB l4 o4 v12 q1\n  e g b e | f a > c f | d g b d | e g b e\n\nT l2 o3 v7\n  c2 | f2 | g2 | c2\n\nN l8 v8\n  r c r c | r c r c | r c r c | r c r c\n',
+        "drum": '#TITLE "Drum Beat"\n#COMPOSER "LLM"\n\nA t120 l8 o4 v15 q2\n  c r e r | g r e r | c r e r | g r c r\n\nB l8 o3 v12 q1\n  e r g r | e r g r | e r g r | e r g r\n\nT l4 o2 v7\n  c2 c2 | c2 c2 | c2 c2 | c2 c2\n\nN l16 v10\n  c r c r c r c r | c r c r c r c r\n  c r c r c r c r | c r c r c r c r\n',
+        "empty": '#TITLE "Empty Template"\n#COMPOSER "LLM"\n\nA t120 l4 o4 v15 q2\n  \n\nB l4 o3 v12 q1\n  \n\nT l4 o3 v7\n  \n\nN l4 v10\n  \n',
+    },
+    "pyxel": {
+        "basic": "0: T120 L8 O4 V100 @1\n   C D E F | G A B >C\n\n1: L8 O3 V80 @2\n   E G B R | E G B R\n\n2: L4 O3 V60\n   C2 G2 E2 C2\n\n3: L8 V80\n   C R C R | C R C R\n",
+        "melody": "0: T120 L8 O5 V100 @1\n   C E G E | D F A F | E G B G | C4 R4\n\n1: L8 O4 V80 @2\n   C E G E | C E G E | D F A F | C4 R4\n\n2: L4 O3 V60\n   C2 G2 | A2 F2 | G2 D2 | C2 R2\n\n3: L8 V70\n   C R C R | C R C R | C R C R | C R C R\n",
+        "chord": "0: T120 L4 O4 V90 @1\n   C E G C | F A >C F | G B >D G | C E G C\n\n1: L4 O4 V90 @2\n   E G B E | F A >C F | D G B D | E G B E\n\n2: L2 O3 V60\n   C2 | F2 | G2 | C2\n\n3: L8 V70\n   R C R C | R C R C | R C R C | R C R C\n",
+        "drum": "0: T120 L8 O4 V100 @1\n   C R E R | G R E R | C R E R | G R C R\n\n1: L8 O3 V80 @2\n   E R G R | E R G R | E R G R | E R G R\n\n2: L4 O2 V60\n   C2 C2 | C2 C2 | C2 C2 | C2 C2\n\n3: L16 V80\n   C R C R C R C R | C R C R C R C R\n   C R C R C R C R | C R C R C R C R\n",
+        "empty": "0: T120 L4 O4 V100 @1\n   \n\n1: L4 O3 V80 @2\n   \n\n2: L4 O3 V60\n   \n\n3: L4 V80\n   \n",
+    },
+}
+
+DESCRIPTIONS = {
+    "basic": "基本的な4ch構成（メロディ+和音+ベース+リズム）",
+    "melody": "メロディ重視（Pulse1主旋律、他は伴奏最小限）",
+    "chord": "コード伴奏重視（Pulse2で和音、Triangleでベース）",
+    "drum": "リズム重視（Noise中心のビートパターン）",
+    "empty": "各チャンネルのヘッダーのみ（空のテンプレート）",
+}
+
+
+def get_template(mode: str, template: str) -> tuple[str, str]:
+    mml = TEMPLATES[mode][template]
+    desc = DESCRIPTIONS[template]
+    return mml, desc