Best-known to the public for his one-time regular gig with Doc Severinsen's Tonight Show band, Tompkins is a versatile, swinging pianist with a do-everything technique who is much in demand on the Los Angeles jazz scene. After studying at the New England Conservatory, he moved to New York, recording with Kai Winding and playing at times with Eric Dolphy (1964), Wes Montgomery (1966), the Bob Brookmeyer/Clark Terry quintet (1966), and Benny Goodman (1968). He also played with Bobby Hackett from 1965 to 1970 and the Al Cohn/Zoot Sims quintet (1968-1972). Tompkins moved to Los Angeles in 1971, where he played with the Louie Bellson big bands and joined the Tonight Show band, remaining until Johnny Carson left the show in 1992. His most frequent appearances on records were as a leader and sideman for Concord Jazz in the 1970s, including a gig with Joe Venuti, Live at Concord '77, and a session with Red Norvo, Red and Ross.