The Bee Gees Rhythm Machine was an electronic music keyboard toy, released by Mattel in 1978. The front of the rhythm machine featured 20 keys (A through E) and four buttons. The first three buttons were pressed to synthesize a disco, latin, or pop rhythm, and the fourth controlled the tempo. On the top of the rhythm machine was a tuning knob, capable of adjusting the pitch an octave in either direction, and a volume knob. The rhythm machine required a 9-volt battery and was packaged with a music book.
The Bee Gees Rhythm Machine was used by the German techno group Kraftwerk in their 1981 song "Pocket Calculator", and can be seen in a video here.
Joseph Rivers has created a flash version of the Bee Gees Rhythm Machine, which can be played here .