Dunbar was born in Liverpool, England. He started his professional career in Derry Wilkie and the Pressmen in 1963. In December 1964 he joined Merseybeat group the Mojos, who were renamed Stu James & the Mojos, with original members vocalist Stu James and guitarist Nick Crouch and Bass player Lewis Collins (later an actor in the Professionals). This line-up continued till 1966. Dunbar then auditioned for the Jimi Hendrix Experience and Hendrix had difficulty deciding between Dunbar and Mitch Mitchell – the latter won Hendrix's coin flip. Dunbar then joined John Mayall's Bluesbreakers replacing Hughie Flint in the summer of 1966. He stayed with Mayall until the spring of 1967 (playing on the A Hard Road album), being replaced by Mick Fleetwood.
After a short stint in the Jeff Beck Group Dunbar founded 'the Aynsley Dunbar Retaliation', so named to chide Mayall who fired him. They issued four albums during their existence. Dunbar co-wrote the song "Warning" (later recorded by Black Sabbath on their first album). The Dunbar single version was recorded in 1967 for the Blue Horizon label, prior to his band's first album release The Aynsley Dunbar Retaliation (circa 1969).
Subsequently, Dunbar founded a short-lived progressive rock band called Blue Whale, which debuted with a tour of Scandinavia in January 1970. Following the recent collapse of the original lineup of King Crimson, Dunbar unsuccessfully tried to recruit Robert Fripp as Blue Whale's guitarist. Fripp, in turn, unsuccessfully tried to recruit Dunbar as King Crimson's new drummer. Blue Whale recorded one album, which featured Paul Williams (vocals), Ivan Zagni (guitar), Roger Sutton (guitar), Tommy Eyre (from Retaliation, keys) and Peter Friedberg (bass).
In 2008, Dunbar recorded an album of material for Direct Music with Mickey Thomas of Starship, and musicians such as Jake E. Lee, former guitarist for Ozzy Osbourne. The complete recordings of Dunbar's drumming with Frank Zappa at Carnegie Hall in October 1971 were released exactly 40 years later in a four-CD set.
In 2009, the blues album The Bluesmasters featuring Mickey Thomas was released, featuring Dunbar on drums along with Tim Tucker on guitar and Danny Miranda on bass as well as guest stars such as Magic Slim on guitar and vocals.
Tracks : 1. Willing to Fight – 6:48 2. Willie the Pimp – 14:55 3. It's Your Turn – 9:57 4. Days – 5:35 5. Going Home – 8:56
Personnel: – Aynsley Dunbar – drums – Tommy Eyre – organ, piano – Ivan Zagni, Roger Sutton – lead guitars – Paul Williams – vocals – Peter Friedberg – bass – Charles Greetham – saxophone – Edward Reay-Smith – trombone – Colin Caldwell – producer Produces By : Aynsley Dunbar % Colin Caldwell Engineer : Colin Caldwell Recorded March & April 1970 Marquee Studios London