The theremin is an early electronic musical instrument controlled without discernible physical contact from the player.
The theremin, was named after its Russian inventor, Professor Léon Theremin, who invented it in 1928.
The controlling section consists of two metal antennas which sense the position of the player's hands and control oscillators for frequency with one hand, and amplitude (volume) with the other, so it can be played without being touched. The electric signals from the theremin are amplified and sent to a loudspeaker.