It should have been fiction: four teenagers with no more than eight O'levels between them, running and biking and busing and busking all over Liverpool in search of new chords and old guitars, a half-decent drum kit and any gig at all.  They were determined to amount to something - in George's words "We just had this amazing inner feeling of: "We're going to do it'. I don't know why ... we were just cocky" - and make a record (in Ringo's words "You'd kill for that bit of plastic") and make some money and have a laugh and a shout. That would do to be going on with.

Six years later, they were the four most famous and musical young men on earth, the best dressed and on a good day quite the most captivating people anyone could remember. 

The narrative began when Paul met John and clicked at a garden in leafy Liverpool, and ended in high dudgeon in high-end London, is so far fetched that it needs the power of a song punctuating every page to remind you with a joyous jolt that it was all true.

We didn't dream it ... though it came out of John's dream of the "man on a flaming pie" who said: "You are Beatles with an 'A'" It did all happen. The whole wonderful thing did happen, a long time ago, on the Mersey, on the Elbe, by the Thames and the Hudson River.

Sweeping out of the final (and wonderfully old fashioned) 1964 Christmas Shows into the wider world of 1965, the Beatles would soon find themselves figureheads of a movement far beyond 'pop'where a counter-culture/alternative society was made flesh.  National boundaries were presumed to be doomed. Millions of minds were to become expanded and many trousers would soon be Spandex.

The Beatles were now a Transatlantic Phenomenon, a band whose American contemporariespresumed they could do no wrong, would never fail to please with their music, would always go on touring, bringing an annual Christmas-in-August to the great Melting Pot.

But in the years - 1965, '66, '67 - though the music would continue to pour out of them , breaking in great waves over uncharted territory , challenging Reason and warming the heart, the Beatleswould tire of those great sweating stadiums where they now played to screaming crowds whocould no longer hear them.

In the "studio years" (1966 onwards), supported by the steady hand of the great George Martin, they would produce songs which would be forever fresh and which still set the standards against which newcomers have to test themselves.

Greatly turned on by the Spirit of the Age and by the "tea-parties" of those times, the Beatles provided a sound-track for the plottings of the Baby Boomers - millions of them - whose enlightenment (however compromised it may have been by the material world in the harsh times since) still provides a hedge against humankind's grosser instincts

It was the great glory of the Beatles that they could absorb and transmute so much, first in those tiny houses in Liverpool, listening to eclectic 1940's wireless, then to r'n'r and r&b and to Dylanand the poets and soon to music and messages from India.

Unafraid of growth, dogged individuals with a powerful devotion to the group ethic, the Beatlesaccepted each other's offerings and really 'cooked' to make each record a feast that left us breathless with admiration. They never stood still.

And in the end, these last years were a time of plentiful confusion: a time to break down and a time to build up. The Beatles started their own company, Apple Corps, with five creative divisions - records, films etc - and then went public with an offer that anyone with an artistic need could come to them withand get help.

Is there , even now, a machine to count such numbers?

The promise was that all sincere supplicants would be given encouragement, succour, a contractand maybe an envelope full of money. At the same time, the Beatles flew to the foothills of the Himalayas, to learn meditation. There, between sessions with Maharishi, they wrote songs for what would come to be known as The 'White' Album.

When recording started, the songs had come in such profusion that, famously, the White album had thirty of them - enough for two high-class musicals. They sped from one track to another, content that the unity of the album would transcend the disparity in the style and content of the tracks. It was always their strength that they wrote bewitching singles.

The new songs were written to suit themselves; sometimes written alone. This new work could virtually be recorded solo, spontaneously, simply. Following the White album (and the magnificent Hey Jude) they made Let It Be and with the final regal glory of Abbey Road they left their grieving fans a legacy that will never be matched.

In the inevitable breaking down of old liaisons, there was room for growth. John met and married Yoko; Paul met and married Linda. George matured far beyond his years, settled into spiritual space and expressed himself writing classic songs; Ringo was now writing his own numbers and was widely acknowledged as a supreme drummer and a very good actor, To everything there is aseason.

That the rift between the Beatles evolved with much public angst was a pity but this is not a perfect world is it? Relationships, anyway, were repaired long ago.

And in the end, the equation between the love they took and the love they made was intact into infinity.

Derek Taylor