One line in. A section out.
SXTN is the THIRI harmony engine pointed at a single melodic instrument. It hears the note you are playing, resolves the bar you are in, and answers with up to five correctly voiced parts built from your own signal — not a synth approximating it. Three ways to play it.
THIRI VST (beta, macOS)
The desktop plugin, in beta: a VST3 for macOS tested in Ableton Live 11, with three tabs, PERFORM, CHART and TRIGGER. Free during the beta. We ask for feedback and ask you not to redistribute the build.
- FormatVST3
- PlatformmacOS, tested in Ableton Live 11
- StateBeta, free, feedback asked for
HORN SXTN (lab build, not for sale)
The pedal build. Five voices, chord intelligence and live pitch tracking inside a 1.333 ms callback on a stock $399 Elk Stomp, with no server and no network. First place at the Elk Audio Challenge, MUTEK Montreal.
- HardwareStock Elk Stomp
- Worst block1.11 ms of 1.333 ms
- StatePrototype, not for sale
CORIS (lab build)
The voice. The same engine in a browser tab — sing a line and hear it answered in your own voice, formants intact. Nothing to install and no account.
- Runs inAny browser, a microphone
- ShifterPhase vocoder worklet
- StateLab build, playable in a browser
WHAT BOTH RUN
The same decision, wherever it runs
Underneath both is one piece of code that takes a note, a chord and a key and returns the notes that belong with it. Integer arithmetic on fixed memory: no allocation, no waiting, no network. That is what makes it legal inside an audio callback, and what makes the pedal and the plugin agree.
- Golden vectors16,353 matched every build
- Voicingsclose, open, drop2, drop3, jazz
- Modes15, major through lydian dominant
- Charts16 slots, stored relative to the key