THE year is 1965, the month February, the place Nashville, Tennessee. Bob Dylan, then just 24 years old, had journeyed south from New York to record his seventh album, Blonde on Blonde, which some believe to be his best, but, then, it does not want for competition.

Among the assembled musicians were the legendary guitarists Al Kooper and Robbie Robertson who spent long days kicking their heels while they waited for Dylan to turn up, tune in and treat them to the latest outburst of his genius. Over the space of a few weeks they would record songs such as Leopard-Skin-Pill-Box Hat, Rainy Day Women, Visions of Johanna, Sad Eyed Lady of the Lowlands and Just Like a Woman, which would become part of the canon that led this week to Dylan becoming a Nobel literature laureate.

Hovering in the background, brush and pan in hand, was Kris Kristofferson, who at that time was employed as a janitor in the recording studio. What he witnessed, he told me a few decades later when he was staying in Glasgow, was mind-blowing. Police, he recalled, had been stationed round the building to deter unwanted intruders. Had he got to meet Dylan? He laughed. “I wouldn’t have dared talk to him. I’d have been fired.”

What he was permitted to do, however, was eavesdrop on history in the making. As one classic, mould-breaking song after another was unveiled, Kristofferson found himself struggling to find the right way to articulate what he experienced. Eventually, he said, “The only way I could describe it is to say that it was like listening to Keats’ words being put to music composed by Mozart.”

Those of us who have grown up with Dylan’s music as the soundtrack to our lives know what Kristofferson, no mean songwriter himself, is getting at. Dylan has tried to explain – as much to himself as anyone else, it seems to me – how his songs come about. “A song is like a dream, and you try to make it come true,” he wrote in his memoir Chronicles. “They’re like strange countries that you have to enter. You can write a song anywhere, in a railroad compartment, on a boat, on horseback – it helps to be moving.”

Like Robert Burns, of whom he is a huge admirer, Dylan is a restless writer. Like Burns, too, he writes for the page and for performance, and makes little distinction between the two. In the beginning, though, is always the word, the music comes later, when he is satisfied that he has said what he has set out to say.

That what he writes is poetry of a very high order is self-evident to all but the most tin-eared and traditional. Whenever anyone argues to the contrary I quote opening lines of Desolation Row, Dylan’s equivalent of TS Eliot’s Portrait of a Lady:

“They're selling postcards of the hanging, they're painting the passports brown/ The beauty parlor is filled with sailors, the circus is in town/ Here comes the blind commissioner, they've got him in a trance/ One hand is tied to the tight-rope walker, the other is in his pants/ And the riot squad they're restless, they need somewhere to go/ As Lady and I look out tonight, from Desolation Row.”

What has always struck me about Dylan is that even those who know him relatively well invariably find themselves at a loss to explain the source of his genius. They can only wonder at it. Joan Baez once told me how, after a gig, when she and Dylan were a couple, they tried to check into a hotel. But the manager did not want to admit Dylan, who looked like one of the hobos in his songs. Baez wanted to kick up a fuss but Dylan told her to forget it and went off into the night on his own. In the morning he produced a song he’d written as an outlet for his anger.

Paul Simon is another who knows Dylan but doesn’t really know him. In 1999 he and Dylan embarked on a joint tour of venues in the US. Later that year, in a small theatre in New York, I heard Simon ruefully recall that what was meant to be a shared performance turned out to to be him playing second fiddle to Dylan. While he oozed sincerity, he said, Dylan was the personification of irony. “He’s telling you the truth and making fun of you at the same time.”

Americans, it’s often said, don’t do irony. That Dylan does and can still be numbered, by the New York Times, “among the most authentic voices the nation has ever produced” merely contributes to his unknowableness. It is the conclusion that every authority on him, including our own and much-lamented Ian Bell, who wrote two books about him, inevitably comes to. He is not only an artist who doesn’t look back he is also adept at covering his tracks, offering insights into his work that he later retracts or disowns.

It’s as if when he changed his name from Robert Allen Zimmerman to Bob Dylan he gave himself a licence to be whoever he wanted to be, to say whatever he wanted to say.

He was not a representative, still less a spokesman. He was a composite, he concluded in Chronicles, of fellow Minnesotans, including the pioneer aviator Charles Lindbergh, F Scott Fitzgerald, rock ’n’ roller Eddie Cochrane, and Sinclair Lewis, the first – but most emphatically not – the last recipient from the “North Country” of the most coveted literary prize in the world.