Roker was born in Miami but began playing in jazz groups in Philadelphia, at the end of the 50s. He then shifted to New York and worked steadily under dozens of leaders, from Junior Mance and Ben Webster to Bobby Hutcherson and Clifford Jordan. He was an in-house drummer for Blue Note in the late 60s, and worked steadily with Dizzy Gillespie through the 70s. Norman Granz used him on many of his studio dates for Pablo in the 70s and early 80s, and while he then toured with Ray Brown's trio, he became tired of life on the road and has since preferred to spend his time at home in Philadelphia, working as and when he chooses.

Biography from Richard Cook's Jazz Encyclopedia (2005).

If you'd like more information, check out The New Grove Dictionary of Jazz (2002) or The Biographical Encyclopedia of Jazz (2007), both of which are still in print.