acestep Checked

### 3. Using a preset for video background

python tools/music_gen.py --preset tension --duration 20 --output problem_scene.mp3

### Key tips for good results

• **Caption = overall style** (genre, instruments, mood, production quality)
• **Lyrics = temporal structure** (verse/chorus flow, vocal delivery)
• **UPPERCASE in lyrics** = high vocal intensity
• **Parentheses** = background vocals: "We rise (together)"
• **Keep 6-10 syllables per line** for natural rhythm
• **Don't describe the melody in the caption** — describe the *sound* and *feeling*
• **Use --seed** to lock randomness when iterating on prompt/lyrics

Scene Presets

| Preset | BPM | Key | Use Case |

|--------|-----|-----|----------|

| corporate-bg | 110 | C Major | Professional background, presentations |

| upbeat-tech | 128 | G Major | Product launches, tech demos |

| ambient | 72 | D Major | Overview slides, reflective content |

| dramatic | 90 | D Minor | Reveals, announcements |

| tension | 85 | A Minor | Problem statements, challenges |

| hopeful | 120 | C Major | Solution reveals, resolutions |

| cta | 135 | E Major | Call to action, closing energy |

| lofi | 85 | F Major | Screen recordings, coding demos |

Task Types

### text2music (default)

Generate music from text prompt + optional lyrics.

### cover

Style transfer from reference audio. Control blend with --cover-strength (0.0-1.0):

• **0.2** — Loose style inspiration (more creative freedom)
• **0.5** — Balanced style transfer
• **0.7** — Close to original structure (default)
• **1.0** — Maximum fidelity to source

### extract

Stem separation — isolate individual tracks from mixed audio.

Tracks: vocals, drums, bass, guitar, piano, keyboard, strings, brass, woodwinds, other

### repaint (future)

Regenerate a specific time segment within existing audio while preserving the rest.

### lego (future, requires base model)

Generate individual instrument tracks within an existing audio context.

### complete (future, requires base model)

Extend partial compositions by adding specified instruments.

Prompt Engineering

### Caption Writing — Layer Dimensions

Write captions by layering multiple descriptive dimensions rather than single-word descriptions.

**Dimensions to include:**

• **Genre/Style**: pop, rock, jazz, electronic, lo-fi, synthwave, orchestral
• **Emotion/Mood**: melancholic, euphoric, dreamy, nostalgic, intimate, tense
• **Instruments**: acoustic guitar, synth pads, 808 drums, strings, brass, piano
• **Timbre**: warm, crisp, airy, punchy, lush, polished, raw
• **Era**: "80s synth-pop", "modern indie", "classical romantic"
• **Production**: lo-fi, studio-polished, live recording, cinematic
• **Vocal**: breathy, powerful, falsetto, raspy, spoken word (or "instrumental")

**Good**: "Slow melancholic piano ballad with intimate female vocal, warm strings building to powerful chorus, studio-polished production"

**Bad**: "Sad song"

### Key Principles

1. **Specificity over vagueness** — describe instruments, mood, production style

2. **Avoid contradictions** — don't request "classical strings" and "hardcore metal" simultaneously

3. **Repetition reinforces priority** — repeat important elements for emphasis

4. **Sparse captions = more creative freedom** — detailed captions constrain the model

5. **Use metadata params for BPM/key** — don't write "120 BPM" in the caption, use --bpm 120

### Lyrics Formatting

**Structure tags** (use in lyrics, not caption):

[Intro]
[Verse]
[Chorus]
[Bridge]
[Outro]
[Instrumental]
[Guitar Solo]
[Build]
[Drop]
[Breakdown]

**Vocal control** (prefix lines or sections):

[raspy vocal]
[whispered]
[falsetto]
[powerful belting]
[harmonies]
[ad-lib]

**Energy indicators:**

• UPPERCASE = high intensity ("WE RISE ABOVE")
• Parentheses = background vocals ("We rise (together)")
• Keep 6-10 syllables per line within sections for natural rhythm

**Example — Tech Product Jingle:**

[Verse]
Build it better, ship it faster
Every feature tells a story

[Chorus - anthemic]
THIS IS YOUR PLATFORM
Your vision, your stage
Digital Samba, every page

[Outro - fade]
(Build it better...)

Video Production Integration

### Music for Scene Types

| Scene | Preset | Duration | Notes |

|-------|--------|----------|-------|

| Title | dramatic or ambient | 3-5s | Short, mood-setting |

| Problem | tension | 10-15s | Dark, unsettling |

| Solution | hopeful | 10-15s | Relief, optimism |

| Demo | lofi or corporate-bg | 30-120s | Non-distracting, matches demo length |

| Stats | upbeat-tech | 8-12s | Building credibility |

| CTA | cta | 5-10s | Maximum energy, punchy |

| Credits | ambient | 5-10s | Gentle fade-out |

### Timing Workflow

1. Plan scene durations first (from voiceover script)

2. Generate music to match: --duration <scene_seconds>

3. Music duration is precise (within 0.1s of requested)

4. For background music spanning multiple scenes: generate one long track

### Combining with Voiceover

Background music should be mixed at 10-20% volume in Remotion:

<Audio src={staticFile('voiceover.mp3')} volume={1} />
<Audio src={staticFile('bg-music.mp3')} volume={0.15} />

For music under narration: use instrumental presets (corporate-bg, ambient, lofi).

For music-forward scenes (title, CTA): can use higher volume or vocal tracks.

### Brand Consistency

Use --brand <name> to load hints from `brand