Looking back at his time with The Beatles, Sir Paul McCartney recently revealed that the group breaking up took a severe toll on him and led him to drinking. He even confessed to thinking about quitting music at the time.

Recording a session of Mastertapes for Radio 4, he spoke about the difficulties he faced in moving forward from the Beatles. "It was difficult to know what to do after The Beatles. How do you follow that?" he said, in conversation with BBC broadcaster John Wilson.

"I was breaking from my lifelong friends, not knowing whether I was going to continue in music. I took to the bevvies. I took to a wee dram. It was great at first, then suddenly I wasn't having a good time. It wasn't working. I wanted to get back to square one, so I ended up forming Wings," he told the audience, which included celebrities likes Brad Pitt, James Bay and Paul Weller.

The Beatles officially broke up in 1970 but the seeds of discord had been planted close to a year before, when the band hired Allen Klein as their manager against McCartney's wishes. Further changes in the business structure soon led to a falling out between him and John Lennon.

"The business thing split us apart," he said, adding that all the "heavy meetings" were "doing my head in". Once depression kicked in, the singer said that he wasn't sure "whether I was still going to continue in music".

By 1980, he decided to mend things with Lennon and get in touch with him from time to time. "I was really grateful that we got it back together before he died. Because it would have been very difficult to deal with if... well, it was very difficult anyway."

Playing a few bars from Here Today, McCartney explained why he wrote the song about Lennon. "When I was thinking of all the things I never said to him. I'm quite private and don't like to give too much away. Why should people know my innermost thoughts? But a song is the place to put them. In Here Today I say to John, 'I love you'," he revealed.

"I couldn't have said that to him unless we were extremely drunk — I love you, man! But you can put these emotions, these deeper and sometimes awkward truths, in a song."

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