# Sequina

> A bright three-operator FM voice: a sharp, glassy attack that decays fast, for electric pianos, bells and slap basses.

- Instrument id: `org.sournd.instrument.sequina`
- Kind: instrument (a synth you play with notes, keys or MIDI)
- Voices: 16 voices
- Tier: Free
- Version: 0.1.0
- Price: free: a closed library, free to use in your plugins, downloaded with no account or email

## Get it

Download it with no account or email: https://sournd.com/download/free/macos (macOS universal) or https://sournd.com/download/free/linux (Linux x86_64 and aarch64). One archive with every free engine and synth: static library, C headers, README. An AI agent can fetch the links with the MCP tool `get_free_download` at https://sournd.com/mcp.

## Parameters

| Id | Key | Name | Min | Max | Default | Unit |
|---|---|---|---|---|---|---|
| 0 | `fm_index` | FM depth | 0 | 12 | 2.5 | - |
| 1 | `feedback` | Feedback | 0 | 1 | 0 | - |
| 2 | `filter_attack` | Tone attack | 0.5 | 10000 | 1 | ms |
| 3 | `filter_decay` | Tone decay | 5 | 10000 | 450 | ms |
| 4 | `filter_sustain` | Tone sustain | 0 | 1 | 0.15 | - |
| 5 | `filter_release` | Tone release | 5 | 10000 | 400 | ms |
| 6 | `attack` | Attack | 0.5 | 10000 | 1 | ms |
| 7 | `decay` | Decay | 5 | 10000 | 1600 | ms |
| 8 | `sustain` | Sustain | 0 | 1 | 0.25 | - |
| 9 | `release` | Release | 5 | 10000 | 500 | ms |
| 10 | `noise` | Noise | 0 | 1 | 0 | - |
| 11 | `glide` | Glide | 0 | 2000 | 0 | ms |
| 12 | `vibrato_rate` | Vibrato rate | 0.02 | 40 | 5.5 | Hz |
| 13 | `vibrato` | Vibrato | 0 | 100 | 0 | cents |
| 14 | `drift` | Drift | 0 | 25 | 0 | cents |
| 15 | `velocity_amp` | Velocity to level | 0 | 1 | 0.5 | - |
| 16 | `bend_range` | Bend range | 0 | 24 | 2 | st |
| 17 | `width` | Width | 0 | 2 | 1 | x |

## Play it from code

Instruments use the same C ABI as effects, plus note input: `sournd_engine_note_on(e, note, velocity, sample_offset)`, `sournd_engine_note_off(e, note, sample_offset)` and `sournd_engine_all_notes_off(e)`. In JUCE, the bridge feeds your `MidiBuffer` straight in. See the [C ABI reference](https://sournd.com/docs/abi/index.md).