Inventor of the Theremin, an electronic musical instrument.
At the height of his popularity in the 1930's in New York City, he was
kidnapped by Soviet agents, under direct orders by Stalin, and brought
back to the Soviet Union, where he was forced to design electronic
surveillence devices.
His development of the theremin, the first uniquely electronic musical
instrument, is even more astonishing when one considers it was invented
before the oscilloscope!