Documentation Index

Fetch the complete documentation index at: https://docs.modelslab.com/llms.txt

Use this file to discover all available pages before exploring further.

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Song Generation Guide

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Overview

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Key Features

• Duration Control: Generate songs from 30 seconds to 8 minutes (30-480 seconds)
• 50+ Languages: Support for languages from Arabic to Chinese
• Lyrics Generation: Automatic lyrics generation or use your own
• Instrumental Mode: Generate instrumental versions without vocals
• Style Control: Use caption to define music style, instruments, and atmosphere

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Understanding the Parameters

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Caption: Your Music Blueprint

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What to Include in Caption

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Caption Writing Principles

1. Be Specific — “sad piano ballad with female breathy vocal” works better than “a sad song”
2. Combine Dimensions — Mix style + emotion + instruments + timbre for precise control
3. Use References — ”80s synthwave style” or “reggaeton with flamenco influence” conveys complex aesthetics quickly
4. Texture Words Matter — Adjectives like warm, crisp, airy, punchy influence mixing and timbre
5. Balance Detail vs Freedom — More details = more control, fewer details = more AI creativity
6. Avoid Conflicts — Don’t combine incompatible styles like “classical strings” and “hardcore metal” unless you want evolution

A modern reggaeton track with strong flamenco influence, featuring female vocal with reverb,
deep sub-bass, crisp percussion, and plucked synth guitar riff

Lo-fi hip-hop beat with warm vinyl crackle, mellow piano chords, subtle jazz drums,
and atmospheric pad textures

80s synthwave pop with bright synth leads, punchy drum machine, nostalgic atmosphere,
and powerful female vocals

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Lyrics: Your Song’s Timeline

• Lyric text content
• Structure tags ([Verse], [Chorus], etc.)
• Vocal style hints
• Instrumental sections
• Energy changes

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Common Structure Tags

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Vocal Control Tags

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Energy Tags

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Lyrics Writing Tips

[Verse]
walking through the empty streets (normal)

[Chorus]
WE ARE THE CHAMPIONS! (high intensity)

[Chorus]
We rise together (together)
Into the light (into the light)

[Verse 1]
First verse lyrics here
Continue first verse

[Chorus]
Chorus lyrics here
Chorus continues

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Keep Caption and Lyrics Consistent

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

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Duration Calculation

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Estimation Method

• Per line of lyrics: 3-5 seconds
• Intro/Outro: 5-10 seconds each
• Instrumental sections: 5-15 seconds
• Typical structures:
  • 2 verses + 2 choruses: 120-150 seconds minimum
  • 2 verses + 2 choruses + bridge: 180-240 seconds
  • Full song with intro/outro: 210-270 seconds (3.5-4.5 minutes)

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Common Pitfall

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Using Lyrics Generation

1. prompt: Describe the topic/theme for lyrics
2. caption: Describe the music style (same as with manual lyrics)

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Example Request with Lyrics Generation

{
  "key": "your_api_key",
  "lyrics_generation": true,
  "prompt": "A song about overcoming challenges and finding inner strength, with uplifting message and emotional journey from doubt to confidence",
  "caption": "Inspiring pop ballad with piano and strings, building from intimate verse to powerful anthemic chorus, female vocal with emotional delivery",
  "duration": 180,
  "webhook": null,
  "track_id": null
}

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Instrumental Mode

{
  "key": "your_api_key",
  "lyrics_generation": false,
  "lyrics": "[Instrumental]",
  "caption": "Energetic electronic dance music with driving bassline, synth melodies, and dynamic build-ups",
  "instrumental": true,
  "duration": 240,
  "webhook": null,
  "track_id": null
}

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Language Support

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Complete Example

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Reggaeton Track with Manual Lyrics

{
  "key": "your_api_key",
  "lyrics_generation": false,
  "lyrics": "[Intro: Sampled Vocal Loop]
(Oh-oh-oh-oh-oh-oh-oh-oh)

[Chorus]
Esta noche todo te lo daré
Es libre ya no me amarraré
Grita mi nombre, dime que me quieres
Me pierdo en tus ojos como si fuera nieve

[Verse 1]
Tus ojos me hipnotizan, me hacen suspirar
Tus labios me llaman, no puedo escapar
Tus manos me tocan, siento la pasión
Cada latido es una explosión

[Chorus]
Esta noche todo te lo daré
Es libre ya no me amarraré
Grita mi nombre, dime que me quieres
Me pierdo en tus ojos como si fuera nieve

[Bridge - whispered]
Solo un instante
Deja que te acerque, ven a mí

[Final Chorus]
Esta noche todo te lo daré
Entre tus brazos me quedaré
Grita mi nombre, dime que me quieres
Me pierdo en tus ojos como si fuera nieve

[Outro]
Solo una noche más",
  "caption": "A modern reggaeton track with strong flamenco influence, opening with pitched vocal sample over dembow beat. Clear confident female vocal in Spanish with reverb. Deep sub-bass, crisp drum machine, plucked synth guitar riff. Layered vocals in chorus, atmospheric bridge, sparse whispered outro.",
  "duration": 199,
  "language": "es",
  "webhook": null,
  "track_id": null
}

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Analysis

• ✅ Caption says “reggaeton with flamenco” → Lyrics in Spanish with reggaeton structure
• ✅ Caption says “confident female vocal” → Lyrics tone matches
• ✅ Caption mentions “whispered outro” → Lyrics has [Bridge - whispered]
• ✅ Duration 199 seconds appropriate for lyrics amount

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Best Practices Summary

1. Caption First — Spend time crafting detailed, specific caption
2. Consistent Description — Ensure caption and lyrics tell the same story
3. Calculate Duration — Count lyrics lines and sections, then estimate time
4. Use Structure Tags — Clear sections improve song structure
5. Test Iterations — Start simple, then refine based on results
6. Language Matters — Set correct language code for best pronunciation

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Common Mistakes to Avoid

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Getting Started

1. Start with Song Generator API Reference
2. Try simple examples first
3. Iterate on caption and lyrics
4. Use webhooks for async processing
5. Join our Discord for community support