At the end of W.W.I, Maurice Martenot (1898-1980), a sergeant in charge of a wireless station, noticed the purity of vibrations produced by radio tubes (a recent invention).
This led to a series of investigations in sound and electronics. He presented his new musical instrument to the public in may of 1928 at the Paris Opera. The first concert with an electronic instrument.
He called his invention the Ondes Martenot (Martenot's waves).
Hundreds of symphonic works, operas, ballets, film scores, and other works were composed for the Martenot by composers such as Olivier Messian, Milhaud, Varese, Boulez, Honneger and more.
Video Demonstration by Jean Laurendeau
Radiohead Pyramid Song with Ondes Martenot