. Other alternating band members between 1978 and 1986 included Billy Blackwood (cousin of Terry Blackwood) on drums, John Mays on bass, Mark Hughes on bass (later with Dobie Gray and owner the world's largest used music store, Mr Mark's Music in Nashville (1980–90, 2000-2016-current), Jeff Chambers on guitars, Randy Dennis on keyboards, David Ennis (later with country group Restless Heart) on keyboards, Gerritt Wilson on Synths, David Hassell on keyboards and vocals, Mark Burchfield on bass