Born on 1 August 1924, in East Ham, Essex (now London), Alan Dean was a vocalist and typical figure of the immediate post-war band era. He worked with the biggest bands of the day, and formed the Song Pedlars vocal group. He later updated the vocal group concept by forming the Keynotes. Dean himself won the Melody Maker poll two years running. He had a light toned ballad voice, but he was also a bopper, and in this context composed some fast moving but melodic bop lines, notably Galaxy and First Gear, using his voice as an additional horn, plus some scatting.

He was the nominal leader of the All Star Sextet which made its debut at the Downbeat Club on 13 March 1948. The declared intention of the Sextet was to play only bebop, and it was probably the first UK bebop-orientated group to play the clubs; they certainly played enough to qualify as a regular group.

Dean was married three times: firstly, to Muriel, who predeceased him, then to Diana, whom he was divorced from. His final wife was Maralyn. He died on 20 October 2018 in Sydney, aged 94.