METALLICA welcomed a special guest to its Bay Area headquarters, fellow San Francisco legend Carlos Santana. The guitar legend is friends with the METALLICA boys and he stopped down on Wednesday (Jan. 22), but reports of a collaboration are premature. Sources say they're just friends, and chat focused around music industry stories and comparing yesterday's music to today's music.Santana is set to perform at the Super Bowl on Sunday (January 26), and METALLICA played an impromptu show in Oakland before the Raiders-Tennessee Titans AFC Championship game last Sunday (Jan. 19). Could a Super Bowl collaboration be a last-minute coup? The band is pro-Raiders and even have a replica of Raiders wide receiver Jerry Rice's jersey hung up in the studio. In a taped message, Lars offered fans three guesses as to who the band was auditioning for the vacant bass player position, but left people hanging in suspense. As previously reported, the band is auditioning bass players for its forthcoming studio album, which is expected late this summer. Studio duties are currently being handled by producer Bob Rock.