The simplest growth model there is — add a cell anywhere on the boundary, at random, forever — whose surface roughens with the exponents of the KPZ universality class, the same ones a burning paper edge and a growing bacterial colony have; the growth rate follows the beat.
Drawn with: a WebGL2 shader.
Reacts to and looks like: gpu, webgl2 and audio-reactive.
Family: Visualiser.
Runs in your browser. The preview above is the same program the renderer uses.