Select a section to edit its chords and drums. Song mode plays them in order.
04 / Harmonic enginePLAY PADS / 1–4
Edit each pad’s root and chord type below. OCT transposes all pads. The scene advances every bar.
05 / Rhythm machine16 STEPS
Tap steps to edit.
✳ Neural atelier
Describe a world. Turn it into sound. AI designs the patch, harmony and groove. You perform the result.
C3 — C5
RETURN INSTRUMENTS / O–1
Meet OBSIDIAN.
A real instrument, made for the browser. Sculpt a sound, hold a chord, build a groove. Let AI take you somewhere unexpected.
Starts audio · no microphone access · start at a low volume
USB PERFORMANCE / MPK MINI PLUS
Your hardware. This instrument.
Connect by USB, then enable MIDI. The keyboard plays KEYS / SOUND with velocity, sustain and ±2-semitone pitch bend. Pads 1–4 play drums; pads 5–8 play chord pads. Keys start dry. Switch DRY to FX beside KEYS / SOUND to use the scene effects.
Built-in mapping: pads on channel 10, notes 36–43; knobs CC 16–23 (also 70–77). Keys use the other channels. Hardware programs can differ: Learn each changed control once. Mappings stay on this device. If pads and keys share a channel, set the hardware’s pads to channel 10 to keep every key playable. Mod wheel adds vibrato to separate key sounds; Program Change selects key sounds.
OPERATOR'S NOTES
OBSIDIAN / Operator’s notes
RETURN INSTRUMENTS / WALNUT / O–1 Intelligent polyphonic synthesizer · 24 voices · Web Audio 0 ACTIVE VOICES
An independent instrument by RETURN. No affiliation with other instrument makers. Headphones recommended.
Power on, then Play scene for chords and beats. Hold pads 1–4 or play the piano with your mouse, touch or A W S E D F T G Y H U J K O L P ; keys. Space starts or pauses. Escape stops all sound. Fullscreen expands the instrument to your display; Escape returns to the browser.
Sculpt
Drag the sliders over the rotary controls, or focus them and use arrow keys. Choose from 36 sounds in the Patch menu: pads, basses, leads, electric keys, organs, plucks, bells and textures. The five engines use detuned analog oscillators, FM, metallic bells, organ harmonics or pitched noise. All run locally in your browser. Effects are tempo-synced delay and algorithmic reverb.
Independent keyboard sound & USB MIDI
KEYS / SOUND beside the keyboard selects one of 36 patches for the on-screen keys and MIDI keyboard. Clean electric piano is the default keyboard sound. It uses pure oscillators with a quick attack and natural decay, without a noise source. DRY bypasses scene distortion, delay and reverb; switch it to FX to share the scene effects. Follow scene sound uses the main timbre. Connect your MPK mini Plus by USB, click MIDI / USB and Connect MIDI, then grant browser permission. Keys respond to velocity, pitch bend and sustain. Pads on channel 10 trigger drums 1–4 and chords 5–8. Eight knobs control Drift, Sub, Drive, Cutoff, Resonance, Release, Echo and Space. Learn saves alternative hardware mappings on this device. MIDI start/stop messages control playback, and other transport messages can be learned. Browser MIDI support is required; use Chrome or Edge.
Harmony & drum mix
Below each chord pad, choose its root and chord type. Change the global key, voicing or OCT register without stopping the groove; changes apply to new notes. Each drum row has a volume slider from silence to 100%, affecting the entire sound including the snare body. LEVEL controls the full drum mix. These settings are saved with your scene.
AI with a musical job
Scene architect writes a patch, four chords and a 16-step drum groove. Patch sculptor changes only your sound. Evolve uses your current scene as context. Results are real parameter changes, never audio files or a fake chat animation. Undo returns to your previous scene.
Privacy & availability
Only your prompt, mode and current musical settings go to the server and OpenAI. Audio stays in your browser. API keys stay on the server. AI has a shared daily allowance and per-visitor limits; all manual playing works without AI. A saved HTML file needs an internet connection to use the hosted AI.
Performance loop
Choose 1, 2 or 4 bars, then Rec loop. Recording starts on the next bar and automatically loops your played piano or chord-pad notes. Notes snap to sixteenth beats. The loop records your performance, not the factory sequence or drums. Change patches while it plays. Pause with Loop, clear with ×. The loop is included in Save scene. Tempo changes take effect at the next loop cycle.
Save & record
Save scene downloads a JSON scene you can load later. Record captures the instrument's output without a microphone and downloads audio when you stop recording. Your last scene is remembered on this device when browser storage is available.