acestep-songwriting

# 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. **Caption** (`-c`): Style/genre/instruments/emotion description 2. **Lyrics** (`-l`): Complete structured lyrics with tags 3. **Parameters**: `--duration`, `--bpm`, `--key`, `--time-signature`, `--language` --- ## 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. **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" 8. **Don't put BPM/key/tempo in Caption** — Use dedicated parameters instead --- ## 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** | `[Intro]` | 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: ``` ✅ [Chorus - anthemic] ❌ [Chorus - anthemic - stacked harmonies - high energy - powerful - epic] ``` 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 | |-----|--------| | `[raspy vocal]` | Raspy, textured vocals | | `[whispered]` | 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 | |-----|--------| | `[high energy]` | High energy, passionate | | `[low energy]` | Low energy, restrained | | `[building energy]` | Increasing energy | | `[explosive]` | Explosive energy | | `[melancholic]` | Melancholic | | `[euphoric]` | Euphoric | | `[dreamy]` | Dreamy | | `[aggressive]` | Aggressive | ### Lyric Writing Tips 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** — `We rise together (together)` 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. --- ## Music Metadata **Most of the time, let LM auto-infer.** Only set manually when you have clear requirements. | Parameter | Range | Description | |-----------|-------|-------------| | `bpm` | 30–300 | Slow 60–80, mid 90–120, fast 130–180 | | `keyscale` | 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` | --- ## 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. --- Note: Lyrics tags (piano, powerful, whispered) are consistent with Caption (piano ballad, building to powerful chorus, intimate).