Paul McCartney said that both his friendship and rivalry with bandmate John Lennon helped to create some of the greatest songs in music history.

McCartney looks back on their complicated relationship in an excerpt from Paul Du Noyer's new book, Conversations With McCartney, printed in the current issue of MOJO.

As McCartney tells it, Lennon was inspired to record his Double Fantasy album after hearing McCartney's 1980 single, "Coming Up."

"Apparently John heard it when he was in New York," he recalled.

"I saw a John documentary and somebody was saying, 'I brought this record of Paul's to John and played it for him.'

John went, 'Oh f—in' hell, the bastard's done something good! I've gotta work!' I love the idea of forcing him up off his arse."

"I like that, because we were always doing that with each other," Sir Paul added.

"People sometimes see it as an arch rivalry. It wasn't. It was a friendly competition that was actually very necessary."