Let's face it, no figure in the history of rock music is more enigmatic than Bob Dylan.

Though I must admit that this fact probably didn't finally hit me full force until I hovered in the vicinity of the man himself one night backstage at Madison Square Garden in 1998.

Why? Well, just picture the scene: I'm there as a guest of Joni Mitchell and her manager, Steve Macklin, and we're surrounded by the likes of Paul Simon, Meryl Streep, Julia Roberts and some of the most powerful movers and shakers in the American music industry.

Nevertheless, everyone present seems to be waiting for even a momentary audience with Robert Zimmerman or a nod or wave when his dressing room door opens.

In fact, at one point someone shrieks: "Did Zimmie actually receive you? I don't fucking believe it!" as if Dylan really was the Pope of Pop or, at least, its new Godfather now that Sinatra was dead.

You think I'm exaggerating? Okay, picture this scene, too.

Moments later a bouncer pushes even the likes of Paul Simon to one side and says: "Everybody to your seats, we have to clear this area."

And then he's followed by four more minders surrounding Dylan, who is smaller than I expect, pale, gaunt, patently still recovering from his relatively recent heart operation - but almost wholly physically defined by eyes like laser beams and a presence so powerful he may just as well be the only person in Madison Square Garden that night.

Tellingly, after Dylan passes, some smart-ass music executive, obviously pissed off at being pushed into a doorway, quips: "At least we weren't asked to line up, bend down and kiss his ring!"

Either way, last Monday and Tuesday night we all were given an audience, of sorts, with 'Zimmie' and certainly allowed further than ever before into his dressing room when BBC 2 broadcast No Direction Home. Not just because it was based on the first lengthy, in-depth, filmed interview Dylan has ever given - in this case to his manager - but because it was directed by masterful filmmaker Martin Scorsese.

Better still, like his documentary A Personal Journey With Martin Scorsese Through American Movies, this 'picture' was structured 'Last week, we were all allowed further than ever before into 'Zimmie's' dressing room' like an odyssey and perfectly titled with that line from Like A Rolling Stone. It also opened with this seminal quote from Dylan: "I had ambitions to set out and find - like an odyssey - this home I'd left a while back and I couldn't remember where it was, but I was on my way there and encountering what I encountered on the way was how I envisioned it all. I was born very far from where I'm supposed to be, so I'm on my way home."

Aren't we all?

And, as with Dylan's greatest songs, it was these universal resonances that helped make No Direction Home so utterly irresistible.

What music lover couldn't relate to the life-changing moment Dylan described when he recalled finding at the age of 10, in a house his father had bought, a guitar and, perhaps even more influentially, a mahogany gramophone on which there was a 78 called Drifting Too Far From the Shore? Was Dylan indulging in a little of his legendary self-mythologising here?

Probably. But broadcast evidence of Dylan's tendency to romanticise his life and times provided the kind of insights that have rarely been revealed before.

Likewise, when Bob referred to "some kind of strange incantation" he heard as a boy in the voice of Johnny Ray, it sure as hell added another dimension to the oft-quoted list of influences he's cited - such as Hank Williams, Muddy Waters, Woody Guthrie, Liam Clancy, Jack Kerouac, Alan Ginsberg and Rimbaud.

Equally fascinating was the fact that Scorsese located Dylan's art in the context of a broader socio-political context that included his "road to nowhere" origins in Hibbing, Minnesota; a sense of the "paranoia" fired during the Fifties by fears of the atomic bomb; plus the rise of the political idealism represented by JFK, Martin Luther King and the civil rights movement.

BBC Arena series editor Andrew Wall suggested prior to the broadcast that Martin Scorsese regards Dylan's going electric - his move from 'pure' folk music to 'folk rock' circa 1966 - as a metaphor for how "everything started to go wrong in the Sixties with the assassination of Kennedy and Vietnam".

The scant attention paid to this premise probably was the single greatest weakness of the programme so far as this particular viewer is concerned.

Yes, the likes of Joan Baez may have bemoaned Dylan's decreasing political involvement from 1965 onwards. She once said, "the message that comes through from Dylan 1965/1966 is 'let's all go home and smoke pot because there's nothing else we can do'".

But Baez didn't have the balls this time round to relate that kind of political retreatism to Dylan's increasing drug use at that time in the Sixties.

This is something that I, for one, see as the clearest indication of how Bobby, the political baby, failed the second half of the Sixtiesin much the same way that he defined the first half.

Then again, maybe this is a question Dylan and Scorsese will address in the next documentary that must follow No Direction Home - if only because it ends in 1966.

Similarly, by way of compensation if you, like me, hated the fact that gloriously rare Sixties' performances by Dylan were frequently halted mid flight by other aspects of the narrative then do not despair, all the performances, in full, are featured on the DVD and CD versions of No Direction Home. And even if, after watching and listening to all that Dylan material, you still can't crack the enigma of the man himself, don't worry, he probably can't either!