Another of Hite's friends, Henry Vestine (who had been expelled from Frank Zappa's Mothers of Invention for smoking pot), asked if he could join the band and was accepted while keeping Edwards on temporarily. Soon Edwards departed (he went on to form the Stone Poneys with Bobby Kimmel and Linda Ronstadt) and at the same time Frank Cook came in to replace Holmes as their permanent drummer. Cook already had substantial professional experience, having performed with such jazz luminaries as bassist Charlie Haden, trumpeter Chet Baker, and pianist Elmo Hope and had also collaborated with black soul/pop artists such as Shirley Ellis and Dobie Gray.