Born in 1924, Alan Dean was a vocalist and typical figure of the immediate post war band era, working with the premier bands, big and small, along the way forming the Song Pedlars vocal group. He later updated the vocal group concept by forming the Keynotes, Alan personally winning 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 it's debut at the Downbeat Club on March 14th, 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.
(Bio copied from David Taylor's website dedicated to British Modern Jazz
from the 1940's.)