Boss Pocket Dictionary Vol. 1-2 (1984-1985):

For a wide array of clapping effects.

HC-2 Hand Clapper

The HC-2 produces the sound of hand clapping when the pad is tapped
Equipped with a Hall control that allows adjustment of the reverberation level and a Dry control that adjusts the clapping tone, the HC-2 can create a wide range of hand-clapping effects
The HC-2 can be connected to other devices, such as a drum machine or a synthesizer, in order to synchronize the clapping with sounds from other instruments