Before becoming famous for his work in British television, Simpson was
Margot Fonteyn's musical director.
His distinctive music for television was often created using an ensemble of just a couple of horns, clarinet and bass clarinet, percussion and electric organ.
He graduated in Composition and Pianoforte from Melbourne Conservatorium of Music. He was also qualified in Orchestration.
His contribution to British television led director Michael Hayes to describe him as "the UK's answer to Bernard Herrmann".