Douglas passed away at a nursing home in Kent, England on Monday (23Mar15).

He began his career with the London Symphony Orchestra and became a full-time member in 1933 as a pianist, organist, percussionist and celesta player. He also played piano for West End shows during the 1930s and performed for ballets, and at restaurants and cinemas.

While composing his own original music and orchestrating existing pieces, Douglas worked with composers Richard Addinsell and William Walton on film scores for movies including Gaslight, Dangerous Moonlight and Major Barbara.

He became composer Ralph Vaughan Williams' assistant from 1947 until Williams' death in 1958, helping him create symphonies and concertos. He also wrote his own music for radio programmes and documentary films.