The Beatles' success was largely driven by the songwriting prowess of Paul McCartney and John Lennon. They were the dynamic duo behind the band's phenomenal success, whether they were co-writing or independently crafting songs before sharing them with each other.

Paul McCartney said much of what John Lennon said about him stung. He revealed one thing that was particularly hurtful.

One Beatles song would see them bridge the gap between being pop stars and music's icons. One song written by John Lennon that would change the Fab Four forever