Electronic instruments in the form of keyboards that either play a limited number of sounds, often those that mimic acoustic pianos or similar instruments, or that make no sound themselves, but are intended to trigger other devices through control voltage, MIDI, or other means. For electronic instruments that shape or form a great variety of sound wholly from electronic signals, either from analog circuitry or through digital means, and that may or may not have an integral keyboard, use 'synthesizers.'
