This article is about the Swiss electronic group. For the unintentional break when transitioning vocal registers, see voice break. For the unintentional falsetto that occurs during puberty, see voice change.
Voice Crack was a Swiss electronic free improvisation group. Formed in late 1972 by Andy Guhl and Norbert Möslang, Voice Crack were initially a free jazz duo. They began incorporating pre-recorded tape effects and live sound processing, and by 1983 they eliminated any normal instrumentation in favor of what they call "cracked everyday electronics:" Mundane objects such as "radios, turntables, transmitters, dictating machines" and other items are cracked open and manipulated to produce "new sounds using magnetic and radio waves in a complex system controlled by movements of their hands and by light."
The resulting music - which consisted of various overlapping buzzes, clicks, drones and oscillations - has been described as, "Cascading magnetic waves arc across the sky as three-headed critters race and rummage through alien flora ... or at least that's what it sounds like."; and was favorably compared to some of John Cage's work.