Whadda WSG105 Electronic Theremin kit. The Theremin was the first music synthesizer. The Junior Theremin is our, smaller, version of that classic electronic musical instrument. As you move your hand towards and away from the wire aerial, the Theremin responds by changing the pitch of the note it is playing. It can play individual notes as well as varying the tone of a single note. Other uses for this kit includes, EMF & Spiritual Detection, subject to modifications. Who you gunna call?