Beatles song based on Bach?
None of The Beatles had a background in classical music.
George did learn one classical 'party-piece' in his early teens, which he then taught to Paul. They knew it was by J.S. Bach but would only later learn that it was Bourrée from the E Minor Lute Suite.
Paul also discovered that they had been playing the original inaccurately. His version was in essence a variation on the Bourrée This would be the starting point for Blackbird, a song he confesses he still finds hard to play