Originally Posted by
mabmac
The prelude wasn't written as such. Sir William Walton was contracted to write the music for the film Battle of Britain. In the end his music score was not used apart from one dogfighting scene. This music was then reworked as the prelude and given its title.
Correct.
They were so disappointed with Walton's score for the film, they brought Ron Goodwin at last moment and what a job he did in very short space of time with the opening and closing music plus variations of both used during the film as well.