The Syntheslicer is a DIY synth project that lets you really play with your food.
It's an alternate impementation of Adafruit's Drawdio electronics kit that puts the sound generator/synth on a knife.
The Drawdio is a DIY electronic sound generator that attaches to a pencil and uses the conductive properties of graphite to make noise from what you draw.
Hacker Jonathan M. Guberman combined the Drawdio with a knife to make the Syntheslicer. To use it, you hold the Syntheslicer in one hand and a fork with a metallic handle in the other, and you "play with your food" to control the pitch.