Denis was born in Hornchurch, Essex and began his musical career at the age of six as a banjo-playing singer at children’s matinees. By the age of thirteen, he was part of one of the most successful British pop groups of the 50s and 60s, The King Brothers.
With the disbanding of the group in 1968, he studied orchestration at the Guildhall School of Music in London and soon got his first break as a television composer with the theme for Black Beauty, which won the Ivor Novello Award. To date, Denis has created themes and incidental music for over two hundred television series including We’ll Meet Again, Dick Turpin, Hannay, Wish Me Luck and Lovejoy.
His debut as a theatrical composer was with the Royal Shakespeare’s production of Privates on Parade (book and lyrics by Peter Nichols) which won the Ivor Novello Award for Best Musical. Other theatre productions include Lost Empires; Worzel Gummidge (with Keith Waterhouse and Willis Hall); Wind In The Willows; Treasure Island; Stepping Out – The Musical (book by Richard Harris and lyrics by Mary Stewart-David); Baby On Board; A Saint She Ain’t (book and lyrics by Dick Vosburgh); Whenver and Orvin (book and lyrics by Alan Ayckbourn).