Instrument · Instrument
Syrinx
Polyphonic MIDI synthesizer based on the Mindlin-Laje biophysical avian syrinx model, with 10 bird-species presets, chromatic MIDI pitch mapping, and a vertical-slider NanoVG UI.
Opinion
Not bad. Birdish. It lacks the variety of the Lyre site/app on which it is based but is still interesting/useful.
Functionality
Syrinx is a polyphonic synthesizer that models avian vocal production using the Mindlin-Laje ordinary differential equation syrinx model — the same physics that produces birdsong. Each voice runs an explicit Euler ODE at audio rate with optional oversampling, a pitch-tracking bandpass vocal-tract filter, formant bank, respiration model, and noise/roughness source modifiers. The DSP was ported from the glorious Lyrebird project.
It responds chromatically to MIDI note input: note number maps to base frequency (A4 = 440 Hz) and velocity scales amplitude. Up to eight voices play simultaneously with oldest-completed voice stealing.
Presets
Ten built-in presets cover a range of timbres and behaviours:
| # | Name | Character |
|---|---|---|
| 1 | Wren | Fast, complex, high-frequency warble |
| 2 | Thrush | Rich, melodic phrases with formant emphasis |
| 3 | Warbler | Sustained tones with slow vibrato |
| 4 | Finch | Short bright chips, high pitch |
| 5 | Robin | Mid-range, pure, rounded contour |
| 6 | Nightjar | Low raspy churn — noise and roughness |
| 7 | Pigeon | Soft coo, respiration-driven, low coupling |
| 8 | Hummingbird | Ultra-fast AM trill, high pitch |
| 9 | Starling | Buzzy reed timbre, irregular roughness |
| 10 | Custom | Blank default for user patches |
Parameters
Per-preset controls (vertical sliders): Level, Noise, Roughness, Timbre, Vibrato Rate, Vibrato Depth, Contour Bend, Harmonic, AM Rate.
Master controls: Distance (air absorption + reverb mix), Gain.
MIDI
| CC | Parameter |
|---|---|
| 1 | Vibrato Depth |
| 7 | Master Volume |
| 71 | Roughness |
| 74 | Timbre |
| 76 | Vibrato Rate |
| 77 | Noise |
| 91 | Distance |
| 94 | Contour Bend |
Pitch bend is applied per MIDI channel (2 semitones by default, set per channel with RPN 0), and voices are keyed by channel and note, so Retune’s one-note-per-channel output bends each note on its own.
Status
First implementation. DSP core, MIDI handling, and NanoVG vertical-slider UI are complete. Preset tuning and host validation are ongoing.