Drum machine

In 1930–32, the innovative and hard-to-use Rhythmicon was developed by Léon Theremin at the request of Henry Cowell, who wanted an instrument that could play compositions with multiple rhythmic patterns, based on the overtone series, that were far too hard to perform on existing keyboard instruments. The invention could produce sixteen different rhythms, each associated with a particular pitch, either individually or in any combination, including en masse, if desired. Received with considerable interest when it was publicly introduced in 1932, the Rhythmicon was soon set aside by Cowell.