TrashMusic (my name) is a very silly project that we did during the orientation for the Integrated Design and Managemen (IDM) program. It's meant to get students comfortable talking to strangers and doing embarrassing things.
Specifcally, the challenge is to create a musical instrument using only found objects. We were allowed to cheat a little bit with batterys and other commodity items, but by and large the instrument had to have been made from junk.
My innovation, such as it is, was to take advantage of the fact that different parts of a spining disk have the same angular velocity, but different linear velocities. Therefore I was able to get different frequencies off of a CD that I hot glued to a 5V motor. I enhanced the effect by gluing small pieces of tape with different spacings in rings around the disk.