Not New Idea (qv. Lev Theremin) (Score 1)

In the 1920's a Russian inventor by the name of Lev (or Leo) Theremin created a device like this that made sounds as a dancer moved in the 3d field. It's name was 'Terpisichore' after the Muse. The original was powered by fluxes in a radio field. PS - Theremin also created the musical instrument that bears his name (from Clara Barlow, 1940's horror films, the chorus of 'Good Vibrations' by the Beach Boys, etc). He also used to manufacture audio bugs for the KGB and GRU.