“A laser harp is basically a big frame resembling a real harp. There are no strings. Instead, beams of laser light are projected from the bottom of the harp. These beams strike light sensors at the top of the frame. When something (a hand, foot, etc.) blocks the beam, a note is triggered on a synthesizer or some type of tone generator. Theoretically the harp could control anything but I’m interested in its musical possibilities.” Here’s how to make one! [via] Link.
HOW TO – Build a Laserharp