MAKE: Flickr pool user Devowski writed up a turntable to an old keyboard to make a very strange circuit-bent hybrid instrument. From his description:
in the arm of the turntable there are 3 photo cells (light sensors) that are wired into the circuitry of the casio. the record on the player has three red leds mounted on it… when the leds pass under the photo cells, it causes a glitch in the keyboard, making some stange noises.
Link to Flickr post, Link to video on YouTube (via MAKE: Blog)