The Beatles legend sang at a charity concert on Beach Boy Brian Wilson's hit 'God Only Knows' and admits he was very overwhelmed by the opportunity. ''We were doing a benefit together, and I was OK on the actual performance, I held it together, but at the sound check I lost it, because it's very emotional, this song, I find it.
I can sit and think 'Oh my God, I'm singing it with Brian', it just got me. I couldn't do it.''
Paul admits he and bandmate John Lennon used to compete with songwriting, not just with one another but also the Beach Boys, and thinks it inspired them to do better.