26 November 1945, Glasgow, Scotland. After starting out on guitar while he was still a small child, Mullen switched to bass in his early teens. He played in various dance bands in his home town before forming his own trio and reverting to guitar. At the end of the 60s he relocated to London and moved into R&B. In the early 70s he was frequently associated with jazz rock. He joined Brian Auger in Oblivion Express and became the star turn of this underrated group. he worked with other fusion influenced bands including Piblokto!, Paz, the Average White Band, Kokomo (UK) and Herbie Manns group. He also formed an outfit with Dick Morrissey, Morrissey-Mullen, which became one of the best-known jazz rock bands in the UK. The band remained in existence until 1985, after which Mullen led his own small groups. Towards the end of the decade he occasionally appeared again with Morrissey, performing at jazz festivals throughout the UK. He also gained acclaim backing vocalist Claire Martin in duo settings, and remains an in-demand sideman. A dynamic and forceful player, Mullens years in jazz rock and his deep affinity with the blues give his music a quality of earthy excitement.
Source: The Encyclopedia of Popular Music by Colin Larkin. Licensed from Muze.