The theremin is an early electronic instrument invented by Leon Theremin in 1928. Controlled without physical contact, the instrument consists of two metal antennas that sense the relative position of the player’s hands, one for frequency and the other for volume. The electric signals from the theremin are amplified and sent to a loadspeaker.
The instrument has been most widely used in avant-garde music and in film scores. Of course, the occasional theremin player cannot resist trying the instrument out on Bach!
Listen to Variation No. 25 from the Goldberg Variations performed by thereminist, Grégoire Blanc.