JC‑808

Rhythm Composer Twelve analogue-modelled voices, sequencer & synthesiser — built from scratch with the Web Audio API.
120 Tempo
Bank

Rhythm Section

Click steps to build a pattern · ▾ opens level / tune / decay

Synthesiser

+0 Oct

Oscillator

Filter

Envelope

Arpeggiator

Mix & Effects

Output

Controls

Transport

Space
Play / stop
Esc
All notes off
Shift + bank
Copy current bank

Drum pads

1…=
Trigger the twelve voices in order (BD → MA)
Click a name
Audition that voice

Keyboard

ASD…
White keys, C upwards
WET…
Black keys
Z / X
Octave down / up

Knobs

Drag / wheel
Adjust
Shift + drag
Fine
Double-click
Reset to default
Arrow keys
Adjust when focused

Notes

Accent
The bottom lane lifts every hit on that step
Arp
Runs off the sequencer clock — press play, then hold keys
Latch
Each key toggles in and out of the chord; Esc clears it
Export
Renders two passes of the pattern (or the chain) to WAV

JC‑808

Browsers need a click before they'll make a sound. Power on to start the sequencer, or enter quietly and build a pattern first.