[1] Sylvester began his professional music career with the a cappella London Boy Singers chorus in the 1960s, and as a sound engineer in 1969.

[2] Working as an assistant at Abbey Road Studios when The Beatles recorded their eponymous album, he was inspired by Paul McCartney to take up the bass guitar.

He also played in live acts led by Marty Balin, Mary Wells, The Shirelles, The Coasters, The Drifters, Billy Preston, Christine McVie, Steve Seskin, Bo Diddley, Chuck Berry, Freddy Fender, Del Shannon, and Vince Welnick's Missing Man Formation.

[2][3][4] Sylvester also worked with ex-Fleetwood Mac member Bob Welch in his band as a bass player for his concert Live from the Roxy in West Hollywood on November 19th 1981.

[citation needed] Sylvester continued to play occasional shows with jam band alumni like Stu Allen, Ghosts of Electricity, Melvin Seals and JGB, David Nelson & Friends, Jemimah Puddleduck, and the Rubber Souldiers.