The ultimate Lennon-McCartney collaboration, "A Day in the Life" wasn't recognized as the band's masterwork until the Eighties, after Lennon's death. It pairs lyrics inspired by the newspapers and Lennon's own life with McCartney's idea to have classical musicians perform what producer George Martin called an "orchestral orgasm."

For more on "A Day in the Life" and the rest of the 100 greatest Beatles songs, pick up Rolling Stone: The Beatles 100 Greatest Songs on sale at barnesandnoble.com now.