Gridsong

Gridsong is a browser matrix sequencer inspired by Toshio Iwai's and Yamaha's TENORI-ON, the 2007 instrument that turned a 16×16 grid of lit buttons into a musical surface. Time runs left to right across the grid and pitch runs bottom to top, so a lit cell is a note and a pattern of cells is a loop. Sixteen layers stack on top of one another, sixteen blocks hold sixteen arrangements of those layers, and the six performance modes — Score, Random, Draw, Bounce, Push, and Solo — each give the same grid a different way of turning light into sound. The ten function buttons down the sides set tempo, voice, transpose, scale, octave, loop points and the rest, drawing their menus on the LED matrix itself the way the original did.

It began as an experiment in building from documentation alone. I read the owner's manual with an AI model, described the behaviour it specified, and asked for a working simulation — no reference implementation, no samples, no photographs of the interface. The first attempt, a year earlier, produced something recognisable but hollow. Repeating it with a current model produced the instrument you can play here, in a single sitting, including the rules that live only in the manual's footnotes. Comparing the two versions is a fair measure of how far these tools have moved.

Tap the grid to enable sound, then draw. Hold L or R buttons for settings; the block and layer buttons at the top switch arrangements and layers. Plain HTML, CSS and JS with no libraries — the voices are Web Audio patches written from the voice list's names rather than recordings, so they are impressions of the originals, not copies. Gridsong is an independent project, not affiliated with or endorsed by Yamaha. Source on GitHub.