Did you envision a 900-page, seven-year effort [for The Beatles]?

It was closer to eight years, and no, we thought it would be two years. What's being published is actually the sleek, slimmed version. I delivered 2,700 pages, so we cut two-thirds of the book. The material was just so rich and the subjects so fascinating that it took on a larger form.

With so much already written, what drew you to the Beatles?

Between 500 and 700 books! Unfortunately, much of the work on the Beatles hasn't been very good. Paul McCartney told me that the Beatles had agreed on a history of the Beatles when they were about 25; they told that story to Hunter Davies in 1967, and only about 60% of that was true. One of the hardest parts of writing this book was chipping away at the myth and getting the real story. I felt the Beatles deserved a solid biography. I used as my models authors like Robert Caro, Neil Gabler and David McCullough, and I say that with all humility. I always saw this book as a work of history, as well as a cultural biography. I never for a moment wanted it to be anything less.

The Beatles were very different people from the image they cultivated, weren't they?

They contrived an image, which was the one they had to contrive, and that is the four lovable moptops from Liverpool. That was mostly the persona Paul had given the Beatles, and it was also what broke the Beatles up. Everyone thinks it was Yoko, but I firmly believe it was Paul. John and George just couldn't stand to be in the room with him any more. Paul wanted to go on as the moptops, but by Revolver, they'd done in that image.

Could there ever be another Beatles?

No, I don't think so. The Beatles phenomenon stemmed from innocence. It grew in an innocent way. The media covered it in an innocent way in that the Beatles shaped the image, the media didn't. Today, the minute any group is put on the market, there is a media and marketing plan. The Beatles phenomenon was as pure as any phenomenon gets.

Was there anything that really surprised you about them in all the research you did?

What surprised me most was that, even at the end of their association, whenever they went anywhere together, where they had to be as a group, they all checked into a hotel and took one room. I find that completely remarkable. That speaks volumes about who they were and what they did. Deep down, I firmly believe those guys loved each other. Even in their confused states at the very end.