Born in 1921 in Northamptonshire, Arnold was the youngest of five children in a family of shoemakers, according to The Observer of London. He took up the trumpet as a teen after hearing Louis Armstrong perform and attended the Royal College of Music on scholarship. By age 21 he was a principal trumpet with the London Philharmonic Orchestra. His First Symphony was premiered in 1950.
An extraordinarily prolific composer, Arnold wrote the scores for 132 films, according to Reuters, including Whistle Down the Wind, The Belles of St. Trinian's, Hobson's Choice and Bridge on the River Kwai, which he completed in 10 days and for which, in 1958, he became the first British composer to win an Oscar. In addition, he wrote seven ballets, two operas, nine symphonies, more than 20 concertos and a musical.
For his services to music, Queen Elizabeth named Arnold Commander of the British Empire in 1970 and knighted him in 1993.
For all his professional accomplishments, Arnold's personal life was unstable and painful, according to The Observer. He suffered repeated bouts of severe depression and alcoholism, made several suicide attempts and underwent insulin treatments and electroshock therapy. Both of his marriages fell apart. (He is survived by three children.) He was notorious in the music world for ill temper and rude behavior, which kept him from the grand-old-man status he might well have achieved in Britain otherwise.
Cellist Julian Lloyd Webber, speaking to the BBC, described Arnold as a underappreciated "genius" whose value was never fully recognized. "I think he was a very, very great composer but uneven in his output. Because he had humor in his music, he was never fully appreciated by the classical establishment. He was a total genius, but a very badly behaved genius — but then, so was Mozart."
Arnold had his most recent premiere just a few hours after he died. According to the BBC, The Three Musketeers, a new ballet with a score compiled from a number of Arnold's concert works, received its first performance by Northern Ballet Theatre on September 23 at the Alhambra Theatre in Bradford, England.