File:Wurlitzer Sideman drum machine (inside).jpg One of the first drum machines ever built, it used solder connections to register a beat. in 1959 Wurlitzer released an electro-mechanical drum machine called the Sideman, which was the first ever commercially-produced drum machine. The Sideman was intended as a percussive accompaniment for the Wurlitzer organ range. The Sideman offered a choice of 12 electronically generated, predefined rhythm patterns with variable tempos. The sound source was a series of vacuum tubes which created 10 preset electronic drum sounds. The drum sounds were 'sequenced' by a rotating disc with metal contacts across its face, spaced in a certain pattern to generate parts of a particular rhythm. Combinations of these different sets of rhythms and drum sounds created popular rhythmic patterns of the day, e.g. waltzes, fox trots etc. These combinations were selected by a rotary knob on the top of the Sideman box. The tempo of the patterns was controlled by a slider that increased the speed of rotation of the disc. The Sideman had a panel of 10 buttons for manually triggering drum sounds, and a remote player to control the machine while playing from an organ keyboard. The Sideman was housed in a wooden cabinet that contained the sound generating circuitry, amplifier and speaker. http://en.wikipedia.org/wiki/Drum_machine#Early_drum_machines