Sir John Dankworth, CBE (20 September 1927 - 6 February 2010), was an English jazz composer, saxophonist and clarinetist. He was widely thought of as Britain's most famous jazz musician. He had a very big influence in the development of jazz in Britain. He composed film music and several television theme tunes such as "The Avengers" and "Tomorrow's World". In his early career he was known as Johnny Dankworth He was the husband of jazz singer Cleo Laine.