Synthesizer

An electronic instrument, usually with a keyboard, used for the generation and modification of sound. First developed for electronic music studios, the technology evolved to enable concert performance, and eventually digital sound and recording capabilities.

Theremin

One of the earliest electric instruments, first demonstrated in 1920 by the Russian who invented it: Lev Temen, known in English as Leon Theremin. A Theremin player moves his or her hands around the instrument instead of touching it. The two antennae that stick out of it control pitch and volume by transmitting radio waves.