Denis King 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 pop groups of the fifties and sixties, 'The King Brothers'.
With the disbanding of the group in 1968, Denis 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, he has created themes and incidental music for well over one hundred television series, among them We'll Meet Again, Hannay, Dick Turpin, About Face, Lovejoy and Madson.
Denis' debut as a theatrical composer was with the Royal Shakespeare Company's production of Privates on Parade (book and lyrics by Peter Nichols), which won the Ivor Novello for Best Musical. Other theatre productions include Bashville and Valentine's Day (with Benny Green), Lost Empires, Treasure Island, and Worzel Gummidge (with Keith Waterhouse and Willis Hall), Wind in the Willows (with Willis Hall). Stepping Out – The Musical (with Richard Harris and Mary Stewart-David) completed a successful run at the Albery Theatre and Baby on Board (book and lyrics Mary Stewart David) played for a season at the Stephen Joseph Theatre where it was directed by Sir Alan Ayckbourn. A Saint She Ain't (with book and lyrics by Dick Vosburgh) was a resounding success at both the Kings Head, Islington and in London's West End in 1999. It received its American premiere at the Westport Playhouse and Berkshire Theatre Festival in Summer 2002. Denis's next project was to compose the music for a show called Whenever (book and lyrics by Sir Alan Ayckbourn) which had its premiere in Scarborough in December 2000. Michael Grandage's acclaimed production of a revival of Privates on Parade had a sell-out season at The Donmar Warehouse and, more recently, at the Noel Coward Theatre. His musical AWAKING BEAUTY, also with Alan Ayckbourn was premiered in Scarborough in December 2008.