Theremin Style Instrument 

This battery powered electronic musical instrument is a descendant of the theremin and can be played without contact from the musician. This small instrument contains two infared (IR) sensors that measure proximity. One sensor controls the pitch, while the other controls the tone that is played through the speaker in the front. The tone is reflected by one of seven colors that illuminates the center area and highlights a small indicator located on the top panel.

Theremin Style Instrument from Nick Hardeman on Vimeo.