He said: “[Sir Paul McCartney] provided a lightness, an optimism, while I would always go for the sadness, the discords, the bluesy notes.

“There was a period when I thought I didn’t write melodies, that Paul wrote those and I just wrote straight, shouting rock ‘n’ roll.

“But, of course, when I think of some of my own songs—‘In My Life’, or some of the early stuff, ‘This Boy’—I was writing melody with the best of them.”

The pair used this medium to communicate many of their feelings, about the world and issues they were facing.

But who wrote which songs?