If you don’t know what tone matrix is then check out a flash applet based application. It works really amazing. And I believe to replicate it on hardware isn’t easy task at all especially with AVR ATmega328 microcontroller. But here it is a 16×16 LED matrix working as it has to. Each routine is written in assembly language to push processor to the limits.
It generates sound patterns according to sensors activated and these can be modified with four potentiometers. Tone matrix has lots of modes pre-programmed and even well known Game of Life. If make a little improvements with sound quality – this could be a perfect toy for everyone.