Kyle McDonald's sequencer named I Eat Beats features a "tangible and edible music interface" controlled by Skittles. I assume M&Ms and other similarly shaped candies would also work, but it's probably best to use a candy that doesn't melt too easily. You can snack while you sequence—just don't eat all the pieces! Watch the sequencer in action after the jump.
'I Eat Beats' Skittles Sequencer
[via Laughing Squid]