The content originally appeared on: CNN One that grabbed Stephen Colbert was how pianist Billy Preston came to be known as 'the fifth Beatle.' During an interview on his late show that aired on Thanksgiving, Colbert talked with Peter Jackson, who directed the newly released Beatles docuseries. They discussed how Preston came to hop on the keys with the iconic band, made up of John Lennon, Paul McCartney, George Harrison and Ringo Starr. 'He wasn't even supposed to be on […]