The FM-1's four layers painted as a west-coast evening.
Plug the FM-1 into this computer with USB, press Listen to the FM-1 and allow MIDI when the browser asks. MIDI out is on unless you turned it off (GLO, Setup).
The notes go from the FM-1 to this tab and no further: the page sends nothing anywhere.
Pitch sets how far across a note lands, how hard it is played sets how much paint, and the FM-1's tempo sets the wind. The Drone and the Lead keep painting while their notes are held, so the wind draws them out into strokes.
Paint with a finger or the mouse too: the band you touch picks the colour.
Save picture keeps the painting as it is now. Record makes a video of it; with the FM-1 plugged in it records the FM-1's own sound as well, which comes over the same USB cable (the browser asks to use it as a microphone). While it records, the sound moves the wind. Both are saved to this computer and go nowhere else.
It works in Chrome, Edge and Opera, on a computer or an Android phone. Firefox asks you to allow a site permission first. Safari, and every browser on an iPhone or iPad, has no Web MIDI: watch the demo there.
Any MIDI source works: channels 1 to 4 are the Drone, the Sequence, the Lead and Sequence 2, as the FM-1 sends them.
Keys: F full screen, M the ground (vellum, mist or night), D demo, S save picture, R record, H hide this panel. Add ?clean to the address for no panel at all (a projector, or a browser source in OBS).
Part of AISLING (GPL-3.0). No FM-1? Hear it in the browser emulator.