"Sun King and Mean Mr Mustard were two separate songs, but we did record their backing tracks together.
"The same for Polythene Pam and She Came In Through The Bathroom Window - they were recorded together as well. Of course, the overdubs were done on different days and in different studios.
"Each track could have stood on its own, and I suppose Sun King does sound like it's a complete song in its own right. A concept started to come from Paul to tie the songs together, which helped to make the numbers seamless and unified.
"The same thing held true for Golden Slumbers and Carry That Weight: everybody was firmly on board with unifying the songs - well, except for John, who had to be talked into it. He didn't want to do another 'concept album' like Sgt Pepper.
"And then, of course, we get to the famous parts of The End, the drum solo and the three-way guitar solos. The thing that always amused me was how much persuasion it took to get Ringo to play that solo. Usually, you have to try to talk drummers out of doing solos! [laughs] He didn't want to do it, but everybody said, 'No, no, it'll be fantastic!' So he gave in - and turned in a bloody marvelous performance!
"It took a while to get right, and I think Paul helped with some ideas, but it's fantastic. I always want to hear more - that's how good it is. It's so musical, it's not just a drummer going off.
"The idea for guitar solos was very spontaneous and everybody said, 'Yes! Definitely' - well, except for George, who was a little apprehensive at first. But he saw how excited John and Paul were so he went along with it. Truthfully, I think they rather liked the idea of playing together, not really trying to outdo one another per se, but engaging in some real musical bonding.
"Yoko was about to go into the studio with John - this was commonplace by now - and he actually told her, 'No, not now. Let me just do this. It'll just take a minute.' That surprised me a bit. Maybe he felt like he was returning to his roots with the boys - who knows?
"The order was Paul first, then George, then John, and they went back and forth. They ran down their ideas a few times and before you knew it, they were ready to go. Their amps were lined up together and we recorded their parts on one track."
"You could really see the joy in their faces as they played; it was like they were teenagers again. One take was all we needed. The musical telepathy between them was mind-boggling."