Jazz is full of epiphanies. Eddie Condon - wit, prodigious drinker, apologist for traditional jazz and sometime guitar player - described the first time he heard the sound of the great and doomed cornettist, Bix Beiderbecke, as "like a girl saying yes". He wasn't thinking of Molly Bloom. And Miles Davis, when he heard the seminal big-band bop of Billy Eckstine as a teenager in his home town, St Louis, swore it was the most fun he'd ever had with his clothes on.
Which is apt, because Davis has probably been at the centre of more jazz epiphanies in the past 40 years than any other musician, with the possible exception of the hugely influential pianist, Bill Evans. Which is apt, too, because both were part of Kind of Blue, now widely regarded as the finest jazz album ever made and probably lodged as deeply in aficionados' collective consciousness as JFK's visit to Dallas is in the minds of anyone of a certain age.
This particular epiphany took barely nine hours of studio time, including running through new, ground-breaking material to familiarise the musicians with it. There were hardly any completed alternate takes, suggesting that the players didn't find the experience an uphill battle - although the book reveals that bassist Paul Chambers had his problems. And the circumstances of recording were so apparently casual that drummer Jimmy Cobb, the only surviving member of the creme-de-lacreme sextet, said nobody thought it was something special, much less a creation for the ages. It was just a good day at the office.
Time, however, has put the album's quality into perspective and Ashley Khan's well-researched new book, Kind Of Blue: The Making of the Miles Davis Masterpiece, does the same with the circumstances before, during and after its creation - despite the fact that so many of those involved have shuffled off their mortal coils by now, forcing him to seek secondary sources to establish a first-hand sense of how it came about.
To get a feel for the album's creation, however, he had one particular asset: Sony allowed him access to the original Columbia session tapes in full.
It is this which gives the core of the book the resonance and immediacy which are its justification. The rest is context. With Kind Of Blue, Davis and his crucial collaborators - Bill Evans and, possibly, arranger/composer Gil Evans, with whom the trumpeter had already created the great orchestral statements of the Miles Ahead and Porgy and Bess albums for Columbia - was pushing jazz out on to the booby-trapped highway of modal music.
Using modes or scales, he could escape from the tyranny and safety of the preordained chord sequence and challenge the ingenuity and inventiveness of himself and his colleagues. There was no hiding place for self-indulgence or failure of imagination. And if Davis and his front-line colleagues, tenor John Coltrane and alto Cannonball Adderley, succumbed to either commercial pressures or excessive navelgazing later on, for a brief, magical moment the mix, personal and musical, was perfect.
It might not have seemed so at the time. Evans had already left the group months before the March and April 1959 sessions that produced the album, uneasily aware that others in the sextet preferred a more extrovert player.
From the time Evans had joined, scarcely a year before, Davis had laid his requirements on the line to the musically reticent, introverted pianist. He couched his warning in typically explicit sexual terminology. "You got to make it with everybody, you know what I mean? You got to f**k the band," he said.
And Evans was uncomfortable, too, with black audiences who objected to him as the only white face in the sextet, and Davis's constant needling about it, calling him "whitey".
He had been replaced by his predecessor, Red Garland, a pianist for whom "the late" applied as much in life as in death. But Garland did it once too often and Wynton Kelly, a marvellous mix of the spontaneously funky and the cerebrally organised, took his place. Kelly also turned up for the first Kind of Blue session thinking he was on the date, only to find Evans already there. Davis hadn't bothered to tell him it was going to be something different, something more suited to Evans's talents.
That's why Kelly got to play on one track, Freddie Freeloader, a blues and the most conventional piece on the album. He had a phobia about taking the subway and had spent a lot of money on a cab from Brooklyn to make the date, so this was Davis's way of making amends.
On the other hand, the leader seemed less concerned with keeping Evans happy after the album was recorded. Both Blue In Green and Flamenco Sketches, each attributed to Davis on the album, are at the very least jointly composed by Evans and Davis, and the pianist remained bitter, especially about Blue In Green, until the end of his life. After Kind Of Blue, they never recorded together again.
Khan's book is probably at its best looking at the immediate context in which Kind Of Blue was made, although the reminders of Davis's extraordinary nous for discovering and mixing talent, and the accumulation of happenstance that created the sextet, are vital, too. The sessions took place in Columbia's New York studios, converted from an old Greek Orthodox church on 30th Street, below Central Park and well on the way to Greenwich Village, then, as now, the home of most jazz of significance in New York.
As for the original reel-to-reel Scotch tapes, they reveal a studio atmosphere much lighter than the majestic, mournful beauty of the music, with relaxed instructions from Davis, jokes between him and producer Irving Townsend, occasional explanations or queries from Evans, singing and puns from the ebulliently good-natured Adderley, apologies from Chambers. But they also give a sense of how the group worked up to a complete take; in common with Davis's usual practice, once they got that, it was on to the next piece. There is only one exception - the first take of Flamenco Sketches went so well they thought they might do even better with a second.
It's common knowledge now that the master tape used for the album was slightly sharp. Columbia had always used two tape machines, a master and a safety, for recording. In 1992, Mark Wilder, an engineer preparing a reissue, went to the safety, reasoning it was less used, and discovered its pitch was a quarter-tone lower than the album which had been on the market for more than 30 years. The machine on which the master had been recorded had an unsuspected motor problem; the safety had the correct pitch. Nobody, not even the musicians concerned, had noticed the fault. All current reissues are at the correct pitch.
The album was released in 1959 to favourable reviews. Musicians liked it, without necessarily immediately grasping fully what it was about. Pianist Joe Zawinul, later to record with Davis and with the fusion group, Weather Report, thought it was "a nice mellow album, but I don't really remember it turning my head around". By then, Ornette Coleman's blast of freedom and the "New Thing" had hit New York and Kind Of Blue's immediate impact on some musicians was diluted. Time has taken care of that, too.
Although it has acquired a patina of chic since it was recorded - knock three times, show your copy of Kind Of Blue and you're in - it's still a touchstone of what jazz is about. I knew that when I first heard it all those years ago, in a record booth at the back of Mays on St Stephen's Green, now long gone - talk about nostalgia - and rushed out to phone one of my closest friends to tell him to go and buy, ask no questions, the best jazz album I'd ever heard. It still seems like that.
Kind Of Blue: The Making of the Miles Davis Masterpiece, by Ashley Khan, is published by Granta, £20 in UK.