Noise music, often considered an oxymoron, is an extreme form of music incorporating unpleasant sound, rejecting popular and traditional music elements. Sounds are made in noise music using devices such as static, feedback, circuit bending and so on.
Some of the first instances of noise music in popular music were produced by The Beatles (e.g., the tape-loop effects in "Tomorrow Never Knows" and the sound collage "Revolution 9") and, after the band's breakup, continued by John Lennon in his early collaborations with his wife Yoko Ono. Other examples from that period can be found in the work of The Velvet Underground, Frank Zappa and Captain Beefheart. Lou Reed's 1975 recording Metal Machine Music was probably the purest expression of the noise-music esthetic during the rock era. Consisting of an hour of "feedback, distortion, and atonal guitar runs sped up or slowed down" without "rhythms, melodies, or formal structures," the album was reviled by critics but influenced later artists who blended elements of noise music with conventional instrumentation and song structure to generate genres such as noise rock, No Wave and industrial music.