After building acrimony between guitarist-founder Ronnie Montrose and vocalist Sammy Hagar reached a peak during the band's 1974-75 European tour to promote "Paper Money" (as part of the "Warner Bros Music Show" package which also featured Tower of Power, Little Feat, and The Doobie Brothers), Hagar parted ways with the group in February 1975. He was replaced by Los Angeles-based vocalist Bob James. Seeking to further expand and change their sound, the band also drafted keyboardist Jim Alcivar. The "Paper Money" rhythm section of drummer Denny Carmassi and bassist Alan Fitzgerald remained. The new quintet lineup of Montrose made their live debut in San Francisco at Winterland Ballroom on April 5, 1975. At this juncture, the group parted ways with producer Ted Templeman. Montrose released two more albums, the Ronnie Montrose-produced "Warner Brothers Presents... Montrose!" (1975) and "Jump On It" (1976), produced by Jack Douglas, known for his work with Aerosmith. Both albums feature Bob James on vocals and Jim Alcivar on keyboards. On the "Jump On It" album, Alan Fitzgerald was replaced on bass by Randy Jo Hobbs, and the subsequent tour to promote the album saw the band performing as a four-piece without a bass player, utilizing Jim Alicivar for keyboard-bass.