A British drummer born in Preston, Hartley's career began as a replacement for Ringo Starr in Rory Storm and the Hurricanes, a popular Liverpool band.

Hartley then played and recorded with The Artwoods and John Mayall's Bluesbreakers, before forming his own band shortly afterwards, the Keef Hartley Band, which mixed elements of jazz, blues and rock and played at the original Woodstock Festival in 1969. Their sound was compared favourably to Blood, Sweat and Tears.