claude-music-compose

name	claude-music-compose
description	Songwriting guide for ACE-Step music generation. Helps craft captions (style descriptions), lyrics with structure tags, and choose optimal BPM/key/duration/time signature.
when_to_use	Use when user says "compose", "write lyrics", "songwriting", "plan a song", "caption help", or needs guidance before generating music.
model	opus
context	fork
agent	music-composer
allowed-tools	["Read"]

claude-music-compose — Songwriting Assistant

This is a READ-ONLY reference skill. Claude uses this knowledge to help craft optimal inputs for /music generate.

Execution

This sub-skill runs in a forked context (context: fork) and delegates the actual composition planning to the music-composer agent (skills/claude-music/agents/music-composer.md). The agent returns structured JSON ready to hand to music_engine.sh generate.

The reference material below is what the agent reads when it plans. It is also what you read when the user wants to learn the conventions rather than auto-compose.

Output Format

After composing, produce these for the generate command:

1. Caption (-c): Style/genre/instruments/emotion (max 512 chars)
2. Lyrics (-l): Structured lyrics with tags (max 4096 chars)
3. Parameters: --duration, --bpm, --key, --time-sig, --language

Caption Crafting

Formula: Genre + mood + instruments + vocal style + production quality

Dimensions

Dimension	Examples
Genre	pop, rock, jazz, electronic, hip-hop, R&B, folk, classical, lo-fi, synthwave
Mood	melancholic, uplifting, energetic, dreamy, dark, nostalgic, euphoric, intimate
Instruments	acoustic guitar, piano, synth pads, 808 drums, strings, brass, electric bass
Timbre	warm, bright, crisp, airy, punchy, lush, raw, polished
Era	80s synth-pop, 90s grunge, 2010s EDM, vintage soul, modern trap
Production	lo-fi, high-fidelity, live recording, studio-polished, bedroom pop
Vocals	female vocal, male vocal, breathy, powerful, falsetto, raspy, choir
Rhythm	slow tempo, mid-tempo, fast-paced, groovy, driving, laid-back

Principles

1. Specific beats vague — "sad piano ballad, female breathy vocal" > "a sad song"
2. Combine 3-5 dimensions — anchors the direction precisely
3. Don't put BPM/key in caption — use dedicated parameters instead
4. Avoid conflicting genres — "ambient metal" confuses the model
5. Repetition reinforces — repeat elements you want emphasized
6. Less detail = more creativity — let the model surprise you

Lyrics Structure

Tags

Tag	Purpose
[Verse] / [Verse 1]	Narrative sections
[Chorus]	Emotional climax, hook
[Pre-Chorus]	Build energy before chorus
[Bridge]	Transition or elevation
[Intro]	Opening atmosphere
[Outro]	Ending/conclusion
[Drop]	Electronic energy release
[Breakdown]	Reduced instrumentation
[Instrumental]	No vocals section
[Guitar Solo]	Specific instrument solo
[Fade Out]	Fade ending

Density Rules

• ~2-3 words per second of audio
• 30s track: 60-90 words
• 60s track: 120-180 words
• 120s track: 240-360 words
• Keep lines 4-8 words for vocal clarity
• Simple, singable phrasing works best

Tips

• Match lyrics emotion to caption mood
• Avoid tongue twisters and complex vocabulary
• Use line breaks between phrases
• Chorus should be the most memorable/catchy section
• Bridge should contrast with verse/chorus

Parameter Selection

BPM by Genre

Genre	BPM Range	Sweet Spot
Ballad	60-80	70
Lo-fi	70-90	80
R&B	80-100	90
Pop	100-130	120
Rock	110-140	125
House	120-130	125
Hip-hop	80-115	95
EDM	128-150	140
DnB	160-180	174
Trap	130-170	140

Duration Guide

Song Type	Duration	Notes
Jingle/Short	15-30s	TikTok, ad music
Standard	60-120s	Most songs
Full song	180-300s	Complete arrangement
Extended	300-600s	Ambient, DJ sets

For detailed reference: load references/prompt-guide.md and references/music-theory.md