Melka’s using a MIDI track in Ableton Live software to control an LED matrix through his Processing/Arduino setup –

The notes are sent to a Processing sketch, which loads an 8*8 animated gif different for each notes. This gif is processed and the datas are sent to an Arduino board which in return lights a led matrix according to the animated gif.

Unfortunately he doesn’t seem keen on publishing his code, still additional infos available here – Ableton Live Led Matrix