ACE-Step Songwriting Guide

Professional music creation knowledge for writing captions, lyrics, and choosing music parameters for ACE-Step.

Output Format

After using this guide, produce two things for the acestep skill:

1. 1. Caption (-c): Style/genre/instruments/emotion description
2. Lyrics (-l): Complete structured lyrics with tags
3. Parameters: --duration, --bpm, --key, --time-signature, INLINECODE6

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Caption: The Most Important Input

Caption is the most important factor affecting generated music.

Supports multiple formats: simple style words, comma-separated tags, complex natural language descriptions.

Common Dimensions

Dimension	Examples
Style/Genre	pop, rock, jazz, electronic, hip-hop, R&B, folk, classical, lo-fi, synthwave
Emotion/Atmosphere

melancholic, uplifting, energetic, dreamy, dark, nostalgic, euphoric, intimate | | Instruments | acoustic guitar, piano, synth pads, 808 drums, strings, brass, electric bass | | Timbre Texture | warm, bright, crisp, muddy, airy, punchy, lush, raw, polished | | Era Reference | 80s synth-pop, 90s grunge, 2010s EDM, vintage soul, modern trap | | Production Style | lo-fi, high-fidelity, live recording, studio-polished, bedroom pop | | Vocal Characteristics | female vocal, male vocal, breathy, powerful, falsetto, raspy, choir | | Speed/Rhythm | slow tempo, mid-tempo, fast-paced, groovy, driving, laid-back | | Structure Hints | building intro, catchy chorus, dramatic bridge, fade-out ending |

Caption Writing Principles

1. 1. Specific beats vague — "sad piano ballad with female breathy vocal" > "a sad song"
2. Combine multiple dimensions — style+emotion+instruments+timbre anchors direction precisely
3. Use references well — "in the style of 80s synthwave" conveys complex aesthetic quickly
4. Texture words are useful — warm, crisp, airy, punchy influence mixing and timbre
5. Don't pursue perfection — Caption is a starting point, iterate based on results
6. Granularity determines freedom — Less detail = more model creativity; more detail = more control
7. Avoid conflicting words — "classical strings" + "hardcore metal" degrades output

- Fix: Repetition reinforcement — Repeat the elements you want more - Fix: Conflict to evolution — "Start with soft strings, middle becomes metal rock, end turns to hip-hop"

1. 8. Don't put BPM/key/tempo in Caption — Use dedicated parameters instead

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Lyrics: The Temporal Script

Lyrics controls how music unfolds over time. It carries:

• - Lyric text itself
• Structure tags ([Verse], [Chorus], [Bridge]...)
• Vocal style hints ([raspy vocal], [whispered]...)
• Instrumental sections ([guitar solo], [drum break]...)
• Energy changes ([building energy], [explosive drop]...)

Structure Tags

Category	Tag	Description
Basic Structure	INLINECODE7	Opening, establish atmosphere

[Verse] / [Verse 1] | Verse, narrative progression | | | [Pre-Chorus] | Pre-chorus, build energy | | | [Chorus] | Chorus, emotional climax | | | [Bridge] | Bridge, transition or elevation | | | [Outro] | Ending, conclusion | | Dynamic Sections | [Build] | Energy gradually rising | | | [Drop] | Electronic music energy release | | | [Breakdown] | Reduced instrumentation, space | | Instrumental | [Instrumental] | Pure instrumental, no vocals | | | [Guitar Solo] | Guitar solo | | | [Piano Interlude] | Piano interlude | | Special | [Fade Out] | Fade out ending | | | [Silence] | Silence |

Combining Tags

Use - for finer control, but keep it concise:

CODEBLOCK0

Put complex style descriptions in Caption, not in tags.

Caption-Lyrics Consistency

Models are not good at resolving conflicts. Checklist:

• - Instruments in Caption ↔ Instrumental section tags in Lyrics
• Emotion in Caption ↔ Energy tags in Lyrics
• Vocal description in Caption ↔ Vocal control tags in Lyrics

Vocal Control Tags

Tag	Effect
INLINECODE23	Raspy, textured vocals
INLINECODE24

Whispered | | [falsetto] | Falsetto | | [powerful belting] | Powerful, high-pitched singing | | [spoken word] | Rap/recitation | | [harmonies] | Layered harmonies | | [call and response] | Call and response | | [ad-lib] | Improvised embellishments |

Energy and Emotion Tags

Tag	Effect
INLINECODE31	High energy, passionate
INLINECODE32

Low energy, restrained | | [building energy] | Increasing energy | | [explosive] | Explosive energy | | [melancholic] | Melancholic | | [euphoric] | Euphoric | | [dreamy] | Dreamy | | [aggressive] | Aggressive |

Lyric Writing Tips

1. 1. 6-10 syllables per line — Model aligns syllables to beats; keep similar counts for lines in same position (±1-2)
2. Uppercase = stronger intensity — WE ARE THE CHAMPIONS! (shouting) vs walking through the streets (normal)
3. Parentheses = background vocals — INLINECODE41
4. Extend vowels — Feeeling so aliiive (use cautiously, effects unstable)
5. Clear section separation — Blank lines between sections

Avoiding "AI-flavored" Lyrics

Red Flag	Description
Adjective stacking	"neon skies, electric hearts, endless dreams" — vague imagery filler
Rhyme chaos

Inconsistent patterns or forced rhymes breaking meaning | | Blurred boundaries | Lyric content crosses structure tags | | No breathing room | Lines too long to sing in one breath | | Mixed metaphors | Water → fire → flying — listeners can't anchor |

Metaphor discipline: One core metaphor per song, explore its multiple aspects.

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Music Metadata

Most of the time, let LM auto-infer. Only set manually when you have clear requirements.

Parameter	Range	Description
INLINECODE43	30–300	Slow 60–80, mid 90–120, fast 130–180
INLINECODE44

Key | e.g. C Major, Am. Common keys (C, G, D, Am, Em) most stable |
| timesignature | Time sig | 4/4 (most common), 3/4 (waltz), 6/8 (swing) |
| vocal_language | Language | Usually auto-detected from lyrics |
| duration | Seconds | See duration calculation below |

When to Set Manually

Scenario	Set
Daily generation	Let LM auto-infer
Clear tempo requirement

bpm | | Specific style (waltz) | timesignature=3/4 | | Match other material | bpm + duration | | Specific key color | keyscale |

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Duration Calculation

Estimation Method

• - Intro/Outro: 5-10 seconds each
• Instrumental sections: 5-15 seconds each
• Typical structures:

- 2 verses + 2 choruses: 120-150s minimum - 2 verses + 2 choruses + bridge: 180-240s minimum - Full song with intro/outro: 210-270s (3.5-4.5 min)

BPM and Duration Relationship

• - Slower BPM (60-80): Need MORE duration for same lyrics
• Medium BPM (100-130): Standard duration
• Faster BPM (150-180): Can fit more lyrics, but still need breathing room

Rule of thumb: When in doubt, estimate longer. A song too short feels rushed.

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Note: Lyrics tags (piano, powerful, whispered) are consistent with Caption (piano ballad, building to powerful chorus, intimate).