[3] Matthews was also the leader of the musical group The Grodeck Whipperjenny, a psychedelic funkband in the seventies.
[3] Matthews has worked with various musicians, including Bonnie Raitt, Buddy Rich, Idris Muhammad, and the Starland Vocal Band.
He was staff arranger for Creed Taylor's CTI Records label during the mid-1970s, working on albums for artists such as George Benson, Esther Phillips, Grover Washington Jr., Hank Crawford, and Idris Muhammad.
[4][5] In 1978, Matthews arranged strings and orchestra and played piano on Nina Simone's album Baltimore.
[6] Matthews music has been heavily sampled by many hip-hop artists such as The Notorious B.I.G., Nas, MF DOOM, Method Man, Redman and Large Professor and others.