Pop entrepreneur Pete Waterman went so far as to advance the theory that most of the best and most lasting pop records were rooted in notions of melody and harmony derived from European classical music. He declared, "If you look at the greatest pop writers, whether it be Abba... or Lennon and McCartney particularly, because The Beatles' music was very churchy. It was very classical because of [producer] George Martin, there's lots of classical bits he chucks in where he's obviously shown The Beatles different ways of playing the same chord..."
Waterman had started off trying to write something Abba-like. then he discovered that Abba had borrowed a lot of their ideas from Mozart too. On other occasions, Beethoven has proved a handy source of melodies and chord voicings.
Sweeting, A. (2004).Cover Versions. Great Britain: Pimlico.