An electronic musical instrument, such as a guitar or bass guitar, may have a kill switch. It is used infrequently but most commonly in heavy metal music. Contrary to popular belief, a kill switch doesn't break the circuit but works by switching between the hot signal from a pick-up and the ground signal. A typical way of achieving this is (on a guitar with a volume control for each pick-up) by turning down the volume on one of the pick-ups then alternating the pick-up selector switch between that pick-up and one with the volume turned all the way up. They are sometimes used when a singer doubles as a guitar player and isn't playing or sometimes used as an effect during a song. Tom Morello of Rage Against the Machine and Audioslave, and Buckethead (such as in Jordan) are well known for their use of the kill switch. Some amateur guitarists fashion their own kill switches. These are usually very crude but still just as effective as one made by a professional.