A moiré pattern generator with synchronised audio-visual synthesis: what you see and what you hear are driven by the same parameters.
Four pattern families — lines, grid, circles, radial — overlaid with an adjustable angular offset, which is where the moiré interference comes from. Density, angle, scale and speed are all live controls.
The audio side is FM synthesis wired to those same controls, so changing the visual density moves the timbre. It is not sonification bolted on afterwards: both engines share one state.