Long ago when I used to do maintenence on video consoles and pin-ball machines. The pin-ball machine was built with a standard desktop motherboard with additional circuits for the display and sound. If you wetted you finger and ran it along the tracks on the PCB, the audio circuit emitted strange avant garde sounding music. I figure it was the machine equivalent of a DMT trip :]
OH WOW: self-transforming fractal machine elves ;]