He later worked with other local groups, including that of Stuff Smith, as well as with altoist and bandleader Rick Henderson at the Howard Theatre.

[2] He appeared on his first recording in January 1960 with Dorham, saxophonist Charles Davis, pianist Tommy Flanagan, and drummer Buddy Enlow.

Alfred Lion, producer at Blue Note, hired Warren to fill the vacancy of staff bassist.

[2] As sideman, he also recorded with Miles Davis, Hank Mobley, Donald Byrd, Dexter Gordon, Joe Henderson, Jackie McLean, and Stanley Turrentine.

[8] With Donald Byrd With Kenny Dorham With Dexter Gordon With Jackie McLean With Hank Mobley With Thelonious Monk With others