So much has been written about the Beatles, why is this

book different to all other books?

'We know everything there is to know about the Beatles, so what else can possibly be written?' People say that all the time – and I don't agree with it for a second. I wouldn't argue the Beatles' story has been told often, but I would argue that it can't be told again and differently. It's been related the same old way for so very long and it's also dying under the suffocating blanket of 'celebrity'. I want to start again, I want to press the Refresh button.

This is a comprehensive biography, three volumes, a sequential history in which I set out to relate everything that happened, and do so with integrity, attention to detail, accuracy and, I believe, a fair understanding of where the story needs to be told and how to tell it. I'm writing so it unfolds as if in real time – there's no hindsight cleverness, so you get a vivid sense of the forward movement. The Beatles' story always had tremendous energy, speed, vitality – and this must be tangible to the reader.

It all boils down to this. They were four war babies from Liverpool who really did change the world, and whose music and impact still lives on in so many ways, after all these years. I say, let's scrub what we know, or think we know, and start over: Who really were these people, and how did it all happen?

Why three volumes?

Way too much of importance and interest happens in this story to cram into one book. In part, my method has been not to write 'a Beatles book' at all but to write biographies of several lives. It's a thorough biography of John Lennon and of Paul McCartney, of George Harrison, of Richy Starkey, and of the four of them collectively, and it's a biography of George Martin, and of Brian Epstein and others – all woven together with the thread of what was going on around them. I want it to be 'the Beatles in their world and the world about them', so we can see them as people, their lives, personalities, characters, process. It's really a million miles from 'a celeb biography'.

Why All These Years and why Tune In?

The three volumes cover a broad span of time, so all these years seems right straight away, and it reflects that the Beatles have been part of our lives for all these years, a very long time now. I'm trying to write something authentic for those who lived through those days (as I did, I'm pleased to say, and which I think is important) and something instructive/interesting for those who didn't. And it's written for people who don't usually read Beatles books but might realise that, in a very real sense, this is about all our lives. And Tune In because that's the essence of everything, especially the years covered in this first volume. At its most obvious, it's how four lads tuned in to rock and roll, rhythm and blues, country and western and all the other glorious sounds reaching them from the promised land, America. Above all else, it's how these extraordinary main characters tuned into one another.

You made your name with books such as The Complete Beatles Recording Sessions and The Complete Beatles Chronicle. Is All These Years like those, a diary-like reference work? 

No. I wrote those other books in my twenties, and that was what I wanted to do then, and what I felt I could do. Long-form narrative is very much what I want to do now that I'm in my fifties and have a broader world view. The depth of detail is still very much the same, because that's what I love looking for and reporting, but now I need to express it as a read.

You have a long professional association with the Beatles, and some of them individually. Are they involved in Tune In and is this book authorised?

No. I received the odd tiny bit of help which I specifically asked for and they didn't have to give – but substantially no, they're not involved. That's fine, because it's what I expected and what I wanted. This has to be an independent and impartial book. But are the all main players appearing and speaking at the book's core? Yes, constantly. Paul McCartney decided not to talk to me for this particular project, and I completely respect and understand his reasons – but I've interviewed him maybe fifteen times in the past and I've also sourced other quotes of great strength and immediacy for all the players.

One of many reasons the Beatles' achievements and reputation sustain with such integrity is because they were true. They stood for truth, projected truth and lived truthfully as best they could. It's entirely right that their history is written as true as possible, with no embroidery, nothing faked or glossed, nothing stupidly interpreted, everything transparent, everything attributed. Of course my attachment to this subject is deep and lifelong, but I'm not the least bit interested in writing a book simply to say how great they were. They certainly don't need that, and I certainly wouldn't do it. It'd be a waste of my time. My passion is for learning everything I can about this subject, understanding it, and doing my best to set it down clearly so it can be understood relative to what happened.

What period of the story does Tune In cover?

It ends on 31 December 1962, with the Beatles on the cusp of their phenomenal breakthrough, but with everything having fallen well into place – all the people, places, personalities, situations, organisation. So I'm writing about the Liverpool and Hamburg years, the formative years, the teenage years and the childhood years, and all the family backgrounds in a Who Do They Think They Are?-style history – and these families were almost as fascinating as their famous offspring. The three volumes aren't only about 'who these people were' but 'what made them what they were?' I begin this history in 1845; there's a fair deal of Irish blood in the Beatles and I start with the potato famine, which forces the Lennons into Liverpool. Then it moves swiftish through the next hundred years and becomes very solid from the Second World War and the arrival of all the main players.

I'm sure it won't surprise anyone to learn that the Beatles didn't suddenly grow personalities when they had a hit record – that their talent, originality and relentless desire to move on fast, to try new things, was already well in place in their early years. I'm sure no one would be amazed to find the Beatles didn't become instantly remarkable when they conquered Britain, America and much of the world, or funny when they filmed A Hard Day's Night, or inventive when recording Revolver or Sgt Pepper. It was always who they were, a continuation of what was going in all these earlier years, except more visible. The richness of the stories to come in books two and three is also in volume one all the way through. Really, everything was revved up and running in these formative years, in the halls, houses and streets of Liverpool, the only place these people and those events could have happened.

What are your resources?

Everything. Absolutely everything, and this is a book that very much revels in its sources. The Beatles have the richest of history trails and I've spent decades turning up documents, recordings, photos and archive material of every conceivable kind, and – through these things – trying to learn all there is to learn, and make sense of it. I've had more punch-the-air moments on this project, more moments of major discovery, than any other.

The Beatles are the most extraordinary subject to research: there's gold on the surface, gold one layer down, gold, gold, gold, all the way to the nthlevel of discovery. No matter how deep you dig, there it is, another fascinating nugget. I just try to keep an open mind and go where the information might be, where its keepers are. I'm perpetually looking for anything that tells me something new and still it happens every day.