Rainbow 1975, L-R: Soule, Dio, Gruber, Blackmore, Driscoll By Steve Newton Craig Gruber, former bassist for '70s rock acts Elf and Ritchie Blackmore's Rainbow, passed away yesterday after a battle with prostate cancer. News of Gruber's passing was posted on the Facebook page of his former Elf bandmate, keyboardist Mickey Lee Soule: Very sad to hear of … Continue reading Former Elf and Rainbow bassist Craig Gruber dies of prostate cancer at 63