1970-1971; 1973-1975 After disbanded the first incarnation of The Mothers of Invention in 1969, Frank Zappa formed a new version of the Mothers in the early 70's that included Ian Underwood, Jeff Simmons, George Duke, Aynsley Dunbar and singers Mark Volman and Howard Kaylan. Later adding 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