Science teachers might want to check out the video below. It would make a pretty engaging project about electricity, assuming (and you're the experts here) it wouldn't electrocute your students.
Booooooom.com, an art and creativity website, had a contest in which people were asked to make a homemade machine. As it happened the winners both produced machines that make music. Here's one of the winning entries from Buenos Aires, Argentina:
Kraft test drummie & Robert Plant from NormanBates on Vimeo.
According to Booooooom, Cristian Martínez’s submission is a modified toy affixed with metal
sponges, car antennas, and crocodiles clips. He is accompanied by his
friend Isis Abigail on an oscillator, using herself and a plant as
variable resistor. I love how Isis’ really goes off near the end.