MusicGen

Generate electronic music without AI

Requirements

• Rust 1.87.0+

Build

git clone <repository-url>
cd music
cargo build --release

JSON Configuration

Create declaritive songs with structured JSON:

cargo run --bin musicgen json examples/fantasy.json

From Binary

./target/release/musicgen json examples/fantasy.json

Basic JSON Structure

{
  "composition": {
    "key": 60,
    "scale": "minor",
    "tempo": 85.0,
    "measures": 16
  },
  "tracks": [
    {
      "name": "bass",
      "instrument": "sine",
      "volume": 0.8,
      "pattern": {
        "type": "custom",
        "steps": [
          { "time": 0.0, "note": "C2", "duration": 0.75, "velocity": 0.9 }
        ]
      }
    }
  ],
  "export": {
    "filename": "my_song",
    "format": "wav"
  }
}

Definitions

• Track - Each track like a single instrument in a band (like the bass or drums)
• Pattern - The sequence of notes that a track plays.
• Steps - Individual notes in your pattern.
• Velocity - How loud to play the note (0.0 = whisper quiet, 1.0 = full volume)
• Loop Length - How long your pattern is before it repeats (in beats)
• Measures - Groups of beats (usually 4 beats = 1 measure). Like counting "1-2-3-4, 1-2-3-4"
• Tempo/BPM - How fast the song goes. 120 BPM = 120 beats per minute
• Key - What note the song is "centered" around (like C major or A minor)
• MIDI Notes - Just numbers for musical notes. 60 = middle C, 69 = A above middle C. Or use note names like "C4" or "A4"
• Duration - How long a note plays for (in beats). 1.0 = one full beat, 0.5 = half a beat
• Waveforms - The "shape" of the sound. Sine = smooth/warm, Square = retro video game, Sawtooth = buzzy/bright
• Effects - Things that change how your track sounds. Lowpass = makes it muffled, Delay = adds echo
• Time Signature - How many beats per measure. 4/4 means 4 beats per measure (most common)
• Chord - Multiple notes played together. Like C major = C + E + G played at the same time
• Arpeggio - Playing chord notes one after another instead of all together

Available Options

• Instruments: sine, square, sawtooth, triangle, noise, piano
• Scales: major, minor, dorian, pentatonic, blues, chromatic
• Keys: MIDI numbers (60 = C4) or note names ("C4", "F#3")
• Pattern Types: custom, chord, arpeggio, sequence
• Effects: lowpass, highpass, delay, reverb, chorus, distortion

Track Configuration

{
  "tracks": [
    {
      "name": "bass",
      "instrument": "sine",
      "volume": 0.8,
      "pattern": {
        "type": "custom",
        "steps": [
          { "time": 0.0, "note": "C2", "duration": 0.75, "velocity": 0.9 },
          { "time": 2.0, "note": "G2", "duration": 0.75, "velocity": 0.8 }
        ],
        "loop_length": 4.0
      },
      "effects": [
        {
          "type": "lowpass",
          "cutoff": 400.0,
          "resonance": 1.8
        }
      ]
    },
    {
      "name": "drums",
      "instrument": "noise",
      "volume": 0.6,
      "pattern": {
        "type": "custom",
        "steps": [
          { "time": 0.0, "note": "C1", "duration": 0.1, "velocity": 1.0 },
          { "time": 1.0, "note": "E3", "duration": 0.05, "velocity": 0.7 }
        ]
      }
    }
  ]
}

See examples for complete examples and the full schema.

Output

All audio files are saved to the output/ directory.