Frank Zappa joined the R&B group the Soul Giants in 1964. The band included vocalist Ray Collins, bassist Roy Estrada and drummer Jimmy Carl Black. Zappa emerged as their creative leader and changed their name to the Mothers. When they signed Verve Records, their name was changed to The Mothers Of Invention. For much of their seminal 1960's albums, the group also included woodwind player Bunk Gardner, saxophonist Motorhead Sherwood, keyboardist Don Preston, multi-instrumentalist Ian Underwood and additional drummers Billy Mundi and Art Tripp. Most of the members appeared on "Freak Out" (1966), "Absolutely Free" and "We're Only In It For The Money" (1967), "Cruising With Ruben & the Jets" (1968) and "Uncle Meat" (1969).
During Zappa's jazz/classical rock period of 1969-1970, The Mothers were augmented by Don "Sugarcane" Harris (violin), Jean-Luc Ponty (violin), Ruth Underwood (percussion), Aynsley Dunbar and John Guerin (both drums). Most of these members appeared on "Uncle Meat", "Hot Rats", "Weasels Ripped My Flesh" and "Burnt Weeny Sandwich". From 1970-72, Zappa formed a new Mothers with former Turtles members Flo & Eddie (vocalists Mark Volman & Howard Kaylan) and bassist Jim Pons. Don Preston, Ian Underwood and Aynsley Dunbar remained in the lineup, along with additional keyboardist George Duke. After Zappa was pushed from the stage by a fan in 1972 and could not tour for the next year, that lineup of the Mothers was disbanded. Two more jazz rock albums, "Waka Jawaka" and "The Grand Wazoo", were recorded with much of the previous jazz rock group including Preston, Ian and Ruth Underwood, Dunbar, Ponty, Huerin and Duke. Trumpeter Sal Marquez was also added. Zappa and the Mothers went back to vocal rock songs with jazz elements in 1973 on "Over-Nite Sensation", then 1974's "Apostrophe" and 1975's "One Size Fits All". Much of the same band remained, along with new members Bruce Lambourne Fowler (trombone), Tom Fowler (bass) and Napoleon M. Brock (saxophone). In 1975 Zappa stopped using the Mothers of Invention for his backing band. By the late '70s and entirely new backing band was formed with only occasional participation from past Mothers members. Beginning in the 80's, past Mothers members Collins, Black, Gardner, Sherwood, Preston, Tom and Bruce Fowler occasionally played in a Zappa tribute band, The Grandmothers.