Quoted from Many Years From Now:

The opening track on Abbey Road was 'Come Together', recorded in July 1969, a John Lennon song arranged by Paul.

PAUL: He originally brought it over as a very perky little song, and I pointed out to him that it was very similar to Chuck Berry's 'You Can't Catch Me'. John acknowledged it was rather close to it so I said, 'Well, anything you can do to get away from that.' I suggested that we tried it swampy - 'swampy' was the word I used - so we did, we took it right down. I laid that bass line down which very much makes the mood. It's actually a bass line that people now use very often in rap records. If it's not a sample, they use that riff. But that was my contribution to that.

Paul recorded a lot of heavy breathing on the end but it is buried so deep in the mix as to be inaudible. John's copyright infringement was not overlooked by Morris Levy, owner of the Chuck Berry song. Though it was obviously only intended as an affectionate tribute to Berry, it got John into some very deep water in the early seventies when, as compensation, Levy persuaded him to release an album of rock 'n' roIl songs available by mail order only through Levy's company Adam VIII Ltd.

A year after recording 'Come Together', when Paul released the news that the Beatles were effectively disbanded, he told the Evening Standard:

I would love the Beatles to be on top of their form and to be as productive as they were. But things have changed. They're all individuals. Even on Abbey Road we don't do harmonies like we used to. I think it's sad. On 'Come Together' I would have liked to sing harmony with John and I think he would have liked me to but I was too embarrassed to ask him and I don't work to the best of my abilities in that situation.