In 1970, Brewster, with his brother Rick Brewster and Doc Neeson, formed Moonshine Jug & String Band in Adelaide, the band evolved into The Keystone Angels in 1973 An appearance at the 1975 Sunbury Pop Festival, resulted in touring with AC/DC, and with Chuck Berry as his backing band. By the end of 1975 they become The Angels. Other members included Chris Bailey on bass guitar. Brewster left the band and joined The Party Boys in February 1986. He remained with The Party Boys until mid-1989, before teaming up with his friend, Alan Lancaster to form The Bombers.