On-device AI for piano ideas

AI that continues

Play a few notes on an acoustic piano, MIDI keyboard, or the on-screen piano. CoComposer.ai suggests musical continuations that match your take, so you can explore, iterate, and keep the music your own.

Runs on your device Private and offline

Made for musicians Built for piano

Export your music MIDI support

CoComposer.ai running on iPad with MIDI Timeline, takes, and AI generation controls

CoComposer.ai running on iPhone with MIDI Timeline and AI generation controls

A musical partner, not a prompt box

From idea to variation in one flow

Play an idea

Record acoustic piano through your device microphone, use a connected MIDI keyboard, or tap the on-screen piano.

Generate a continuation

Create musical responses that follow your phrasing and timing.

Compare takes

Keep favorite human and AI takes while exploring alternate ideas.

Export MIDI or WAV

Move your compositions into a DAW or notation tool, or share a rendered audio file.

Screenshots

Designed for composing, comparing, and refining

iPad MIDI Timeline with human and AI notes — MIDI Timeline with AI notes

iPad MIDI Timeline note editing controls — Note editing on MIDI Timeline

iPad settings with sound, latency, EQ, subscription, and iCloud sync controls — Sound, sync, and app settings

iPhone MIDI Timeline with takes and AI generation controls — MIDI Timeline on iPhone

iPhone acoustic piano input selected with AI generation controls — Acoustic piano input on iPhone

iPhone Score view with human and AI takes — Score view on iPhone

iPhone MIDI Timeline note editing controls — Note editing on MIDI Timeline

About

Built from a constraint, made for musical freedom

CoComposer.ai was created by Simon Bissonnette, winner in regulation time and second overall in OpenAI's Parameter Golf challenge, where the goal was to train a capable language model under 16 MB.

That challenge turned tiny models into a craft: careful data, careful tokenization, and careful inference. CoComposer.ai applies those lessons to music, with a small piano-focused AI that runs locally instead of sending your ideas to a remote server.

The goal is not to replace musicians with prompts. It is to give artists a responsive sketch partner while keeping copyright, authorship, and creative control close to the person at the keyboard.

Contact

Questions or feedback?

Tell us what you are composing, what feels magical, and what still needs work.

Privacy

Your music stays close

CoComposer.ai generates continuations on your device. Microphone audio stays on your device. If you rate an AI take, anonymous MIDI feedback and model settings may be sent to help improve the model. No name, email, or audio is sent.

Read the Privacy Policy