This video, via Circles Drum Samples, takes a look inside the Wurlitzer Sideman – a vintage (1959) drum machine/rhythm box, based on an electromechanical sequencer and vacuum tube synthesis.
They describe the Sideman as “The World’s First Drum Machine” – but that title depends on what you consider a drum machine. There were earlier electronic rhythm generators – including the late 1940’s Chamberlin Rhythmate, which is like a Mellotron for drum loops, and Henry Cowell & Leon Theremin’s 1932 Rhythmicon, which is more a polyrhythm generator than a drum machine.
Circle Drum Samples has released a sample library based on the Sideman, Drum Machine. It’s available now for US $25.
Let us not forget al-Jazari rockin’ out his (floating!) automata drum machines at parties c. 1200 CE
How are the various rhythms encoded? I only saw one rotating contact wheel and I didn’t see the patterns being changed.
The spinning situation probably triggers all channels all the time in sync and there’s some circuitry to gate then on and off per pattern selection.