Via Spreeblick I found this. It looks to me like a modern day theremin. By attaching it to a computer you can control virtual instruments – so the sound has no boundaries.
The Beamz is a laser-based invention that is connected to a computer via USB. This allows you to play hundreds of musical instruments in a true Jean Michel Jarre style by breaking the laser beams with your hands.
The beamz system has a ‘W’ shape, with six laser beams spanning the two sections; connect via USB to your PC or laptop, and hook up some speakers. The simple, intuitive computer interface makes it easy to choose any of 30 included songs in 19 musical genres for laying down a complementary rhythm track. The beamz library includes original works in jazz, bluegrass, classical, hip-hop, reggae, heavy metal and more