As members of the Beatles, John Lennon and Paul McCartney formed perhaps the greatest songwriting team in the history of pop music. But after the group's members began to bicker, McCartney left the group in 1970 and filed a lawsuit to make the dissolution official [source: Gilmore].
The former collaborators had once been so much in sync that they would go back-and-forth for hours, feeding off one another's lyrical brainstorms. But after the breakup, McCartney's insistence that he enjoyed working solo because "I only had me to ask for a decision" irked Lennon.
In 1971, Lennon responded with a song, "How Do You Sleep?" which was a scathing attack on his fellow ex-Beatle. It contained lines such as "Those freaks was right when they said you was dead"—a taunting reference to conspiracy theories that Paul had died in a car accident and been replaced by a double — and "The only thing you done was Yesterday," a put-down of the Beatles hit associated with McCartney. "The sound you make is Muzak to my ears" likened McCartney's solo work to the canned music played in elevators. Whew, a little bitter, John?
Fortunately, the two mates eventually patched up their differences. In a 1972 TV interview, Lennon said, "If I can't have a fight with my best friend, I don't know who I can have a fight with" [source: Slate].