The Ryhthmicon was the world's first drum machine, built in the 1930s by Leon Theremin (of Theremin fame) for avant grade composer Henry Cowell.
The Rhythmicon relied on photoelectric technology to get the job done. The keys were each connected to a light that turned on when you pressed them. The lights then shined through a sequence of holes punched into two discs that rotated via a motor. On the other side of the discs was a photoelectric sensor that, when activated by the patterns of light, sent the Rhythmicon's unique signals to a tube amp and thus to a speaker and out to dazzled audiences….
Maybe the biggest setback was that it just didn't sound that good. One reviewer, after seeing the Rhythmicon demonstrated with violin accompaniment at a 1932 concert in San Francisco, likened its lower tones to "a cross between a grunt and a snort" and higher notes to "an Indian war whoop."
"The Legend of the Rhythmicon, the World's First Drum Machine" (Red Bull Music Academy Daily)