Instruments

RMT Compose includes several built-in instruments for playback.

Available Instruments

Synth Instruments

Generated in real-time using oscillators:

Instrument	Waveform	Character
sine-wave	Sine	Pure, smooth, mellow
square-wave	Square	Hollow, clarinet-like
sawtooth-wave	Sawtooth	Bright, buzzy, string-like
triangle-wave	Triangle	Soft, flute-like
organ	Complex	Multi-harmonic organ
vibraphone	Complex	Bell-like with vibrato

Sample Instruments

Using pre-recorded samples:

Instrument	Source	Character
piano	Sampled	Acoustic piano
violin	Sampled	Bowed string

Setting Instrument per Note

Using the Variable Widget

1. Select a note
2. Find the instrument dropdown
3. Select from the list

Using Expressions

In module JSON:

{
  "id": 1,
  "frequency": "...",
  "instrument": "sawtooth-wave"
}

Default Instrument

If no instrument is specified:

1. The note inherits from its dependencies
2. If no inheritance, defaults to sine-wave

Instrument Inheritance

Instruments can be inherited through the dependency chain:

// Note 1 has instrument "piano"
note1.instrument = "piano"

// Note 2 doesn't specify instrument
// If note2 depends on note1, it may inherit "piano"
note2.instrument = undefined  // Uses inheritance

Synth Instrument Details

Sine Wave

The simplest waveform - a pure tone with no harmonics.

Best for:

• Pure, clear tones
• Bass frequencies
• Testing pitch relationships

Square Wave

Odd harmonics only (1, 3, 5, 7...).

Best for:

• Clarinet-like tones
• Retro/chiptune sounds
• Bohlen-Pierce scale (odd harmonics)

Sawtooth Wave

All harmonics present (1, 2, 3, 4...).

Best for:

• Bright, rich sounds
• String-like tones
• Lead sounds

Triangle Wave

Odd harmonics, but softer than square.

Best for:

• Soft, mellow tones
• Flute-like sounds
• Gentle melodies

Organ

Multiple simultaneous oscillators simulating organ drawbars.

Best for:

• Full, rich chords
• Sustained passages
• Classical organ music

Vibraphone

Bell-like tone with periodic amplitude modulation.

Best for:

• Mallet percussion simulation
• Jazz voicings
• Ethereal sounds

Sample Instrument Details

Piano

Multi-sampled acoustic piano.

Characteristics:

• Velocity-sensitive dynamics
• Natural decay
• Realistic timbre

Violin

Sampled bowed strings.

Characteristics:

• Sustained tone
• String resonance
• Expressive capability

Mixing Instruments

Different notes can use different instruments:

{
  "notes": [
    { "id": 1, "instrument": "piano", ... },
    { "id": 2, "instrument": "violin", ... },
    { "id": 3, "instrument": "sine-wave", ... }
  ]
}

This enables:

• Ensemble arrangements
• Contrasting timbres
• Highlighting specific voices

Tips

1. Start with sine - It's the clearest for hearing pitch relationships
2. Use square for BP - Odd harmonics match Bohlen-Pierce well
3. Mix for interest - Combine different instruments in a composition
4. Match character - Choose instruments that fit your musical intent
5. Test with playback - Hear how different instruments sound in context

Future Instruments

Planned additions:

• More sample instruments
• Custom sample loading
• FM synthesis
• Audio effects (reverb, delay)

Check the changelog for updates on new instruments.