Bay Area groove-rock combo Hammer comprised singer John DeRoberts, guitarist Jack O'Brien, bassist Richie McBride, keyboardist Norman Landsberg, and drummer John Guerin. Formed in 1969, the group was quickly signed by legendary promoter Bill Graham to his fledgling San Francisco Records label -- their self-titled debut LP appeared in 1970, supported by a series of high-profile opening dates at Graham's Fillmore venues. Despite strong critical notices, Hammer failed to earn much commercial attention, and although a second album was recorded, it was never released and the band dissolved. While Landsberg later collaborated with the Pointer Sisters, Guerin went on to co-found the pioneering fusion unit L.A. Express -- a prolific session drummer, he also played on Joni Mitchell's seminal Court and Spark and The Hissing of Summer Lawns sessions. ~ Jason Ankeny