Phillips began to play professionally at the age of twelve in a dixieland band led by his father, Sid Phillips for 4 years. After his father's death, he started playing pop and rock and found work in a production of the musical "Jesus Christ Superstar". He worked as a session musician for cast members, and this led to other session work. Beginning in the 1970s, he worked with Jeff Beck, Gil Evans, Stanley Clarke, Peter Gabriel, Pete Townshend, and Frank Zappa.