Theremin

The theremin (; originally known as the ætherphone, etherphone, thereminophone or termenvox/thereminvox) is an electronic musical instrument controlled without physical contact by the performer (who is known as a thereminist). It is named after its inventor, Leon Theremin, who patented the device in 1928. The instrument's controlling section usually consists of two metal antennas that function not as radio antennas but rather as position sensors. Each antenna forms one half of a capacitor with each of the thereminist's hands as the other half of the capacitor.