Theremin

THEREMIN
is versatile, experimental and mobile.

The theremin is an early electronic musical instrument controlled without physical contact by the thereminist (performer).
It is named after the Westernized name of its Russian inventor, León Theremin, who patented the device in 1928.
The instrument's controlling section usually consists of two metal antennas that sense the relative position of the thereminist's hands and control oscillators for frequency with one hand, and amplitude (volume) with the other.
The electric signals from the theremin are amplified and sent to a loudspeaker.