The Mothers of Invention were an American rock band from California that served as the backing musicians for Frank Zappa. Their work is marked by the use of sonic experimentation, innovative album art, and elaborate live shows.
Originally an R&B band called The Soul Giants, the band's original lineup included Ray Collins, David Coronado, Ray Hunt, Roy Estrada and Jimmy Carl Black. Zappa was asked to take over as the guitarist following a fight between Collins and Coronado, the band's original saxophonist/leader. Zappa insisted that they perform his original material, changing their name on Mothers Day to The Mothers (which for legal liability reasons was morphed by record executive decision into The Mothers of Invention), and leading them to substantial popular commercial success. Originally formed in 1964, the band first became popular playing in California's underground music scene in the late 1960s. Under Zappa's helm, it was signed to jazz label Verve Records as part of the label's diversification plans. Verve released the Mothers of Invention's début album Freak Out! in 1966, featuring a lineup including Zappa, Collins, Black, Estrada and Elliot Ingber.
Under Zappa's leadership and a changing lineup, the band released a series of critically acclaimed albums, including Absolutely Free, We're Only in It for the Money and Uncle Meat, before being disbanded by Zappa in 1969. In 1970, he formed a new version of the Mothers that included Ian Underwood, Jeff Simmons, George Duke, Aynsley Dunbar and singers Mark Volman and Howard Kaylan (formerly of the Turtles, but who for contractual reasons were credited in this band as the Phlorescent Leech & Eddie). Later adding another ex-Turtle, bassist Jim Pons, this lineup endured through 1971, when Zappa was injured by an audience member during a concert appearance.
Zappa focused on big-band and orchestral music while recovering from his injuries, and in 1973 formed the Mothers' final lineup, which included drummer Ralph Humphrey, trumpeter Sal Marquez, keyboardist/vocalist George Duke, trombonist Bruce Fowler, bassist Tom Fowler, percussionist Ruth Underwood and keyboardist/saxophonist Ian Underwood. The final album using the Mothers as a backing band, Bongo Fury (1975), featured guitarist Denny Walley and drummer Terry Bozzio, who continued to play for Zappa on non-Mothers releases.