Keyboard instruments built from physics.
Every sound here is computed live in your browser from the equations of motion of its instrument — stiff strings and felt hammers, gear-driven tonewheels, steel tines, bouncing contacts, neon lamps, spinning black holes. No samples. Play with your computer keyboard or a MIDI keyboard, and turn the knobs that real instruments hide: the shape of the string, where the hammer lands, how stiff the felt is, how fast the black hole spins.
Each instrument is reduced to its vibrating parts — modes of strings, beams, plates, circuits or spacetime — and integrated sample by sample in an AudioWorklet. Nonlinear parts (hammers, pickups, friction, flames) are solved exactly at every step. Each page explains its equations and shows the physics as you play.
The bottom two letter rows of your keyboard are the white and black keys (Z–/ and Q–]); arrow keys shift the octave and adjust each instrument’s main control. A MIDI keyboard works in Chrome and Edge. Headphones help: some instruments are in stereo for physical reasons.
Everything is plain JavaScript with no build step, MIT-licensed, and checked by physics tests — against textbook cantilevers, published black-hole frequencies, Arnold tongues and more. Each instrument’s README has the equations, the numbers, and what is simplified.