Clara Rockmore - The Art Of The Theremin (1977)...

The theremin (originally pronounced teremin), theramin or thereminvox, also known as an aetherphone is one of the earliest fully electronic musical instruments. It was invented by Russian inventor Léon Theremin in 1919 and it is unique in that it was the first musical instrument designed to be played without being touched. The controlling section generally consists of two metal antennas to sense the relative position of the player's hands. These sensors control audio oscillator(s) for frequency from one hand, and volume from the other. The electric signals from the theremin are amplified and sent to a loudspeaker. To play the theremin, the player moves his hands around the two metal antennas, which control the instrument's frequency (pitch) and amplitude (volume).
Rockmore was without peer as a performer in the early decades of the instrument's use. While many listeners have heard the theremin played poorly or used mostly as a spooky special-effects device, Rockmore used it to perform classical works. Under her control, the theremin sounded like a blend of the cello, violin and human voice.

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