IMPSY - Intelligent MIDI

Jam with an AI MIDI partner on iPad and iPhone.

IMPSY listens to what you play and improvises musical responses. Load it as an AUv3 MIDI Processor in AUM, AudioBus, Cubasis or Logic Pro for iPad, play it from a USB or Bluetooth controller (or the on-screen faders), and route its output to any instrument app. IMPSY also runs on its own: it appears as Core MIDI virtual ports (IMPSY In / IMPSY Out) and connects directly to a plugged-in controller, so you can play it without a DAW.

How it works

IMPSY runs a Mixture Density Recurrent Neural Network (MDRNN) on-device. Every note, control change or pitch-bend you send becomes input to the model, which predicts what comes next, including the timing of the response. Shape the conversation with:

• Threshold: how long IMPSY waits between your input and its reply
• Sigma Temperature: randomness of pitch and control values
• Pi Temperature: randomness of which musical "idea" the model picks
• Timescale: speeds up or slows down the response
• MIDI Thru: passes your own playing through to the output alongside IMPSY's

Connect anything

• Map each model dimension to any MIDI message (notes, CCs or pitch-bend) on any channel, independently for input and output
• Connect a controller directly, or use the always-on IMPSY In / IMPSY Out virtual ports
• Import and export your mappings as TOML, compatible with the IMPSY Python toolkit

Custom models

IMPSY ships with a default 9-dimensional model trained for general musical interaction, but you can load any .tflite model trained with the open-source IMPSY research toolkit: synths, drum machines, lighting rigs, or anything that speaks MIDI.

Accessibility

IMPSY is built to work with VoiceOver and Dynamic Type. Every control is labelled, the sliders are adjustable by VoiceOver, and status shows as text, not colour alone. Full statement: charlesmartin.au/impsy-auv3/accessibility.html

Compatibility

• AUv3 MIDI Processor, no audio I/O
• Hosts in AUM, AudioBus, Cubasis and Logic Pro for iPad, or any other AUv3 host that supports midi processors.
• Also runs standalone with Core MIDI virtual ports and direct device connection
• Requires iOS 17
• MIDI stays on-device. No network, no telemetry