In San Francisco, California Fullerton played with Sam the Sham in 1966, Quicksilver (briefly), and Mount Rushmore, 1967-1969.
He has played drums for Rita Coolidge, Graham Nash, Stephen Stills, Martha Reeves, Billy Joel, and Roxy.
From 1967 to 1980 he toured or recorded with Stephen Stills, Martha Reeves, John Lennon, Mount Rushmore, Quicksilver, Bonnie Raitt, Sylvester, Billy Joel, Lee Oskar, Rita Coolidge, Graham Nash, Roy Buchanan, and many others and played on about 30 albums.
He was signed to major labels including Atlantic, Blue Thumb, Columbia, Paramount, MCA etc.
In the early 1980s his interest in digital music, a computer science degree, and his connection in Los Angeles with Alan Kay, then on the board of directors of Apple Computer, led him to a job there in the "special music projects group."