Circling and re-circling the globe in his “Never Ending Tour” (now in its 17th year), Bob Dylan has managed to obscure himself – if only partly – in the public mind. He has become one of the characters in his songs, half-crazed and half-imagined, “with no direction home / like a complete unknown / like a Rolling Stone.”

Lately, however, he has changed his tack. After four decades of ducking his own myth, he now seems eager to address it (a process that began with last year’s autobiography “Chronicles, Volume One”). “No Direction Home,” Martin Scorsese’s dazzling new documentary of Mr. Dylan’s musical odyssey from 1961-66, benefits greatly from this newfound candor. And, contrary to the burnout image he’s cultivated, the film finds Mr. Dylan still as witty, elusive, and mischievous as ever.

The documentary is divided into two parts, each slightly longer than an hour and a half. The first deals with Mr. Dylan’s youth in sleepy Hibbing, Minn., his rise within the bustling Greenwich Village folk scene, and his “discovery” by legendary talent scout John Hammond. It’s a compelling story in its own right but is made more so by Mr. Scorsese’s decision to intersperse Mr. Dylan’s story with footage from his 1966 tour with the Hawks. We’re left trying to reconcile the sponge-like, wide-eyed boy of 19 with the contemptuous, dead-eyed man of 25. Bridging the gap between them supplies the film’s chief drama.

The highlight of Part 1 is a thorough exploration of the music and milieu that birthed the folk revival and, particularly, Mr. Dylan’s art. Reading Kerouac persuaded him that “the only people who were interesting were the mad ones,” and the young Dylan heard hints of that madness in the voices of Hank Williams, his earliest musical hero, and idiosyncratic folk singers like John Jacob Niles and Odetta (both of whom we see in magical live performances).

Most of all, though, he heard it in Woody Guthrie. “He had a sound, and he said something to go with his sound,” explains Mr. Dylan. “You could listen to his songs and learn how to live.” Which is precisely what Mr. Dylan did, affecting Guthrie’s singular songwriting style (Mr. Dylan’s various talkin’ blues were pitch-perfect acts of mimicry), his voice and dress, even mannerisms. Guthrie also inspired Mr. Dylan’s first “significant” effort at songwriting, “Song to Woody,” which appeared on Mr. Dylan’s 1962 eponymous debut for Columbia.

A colorful group portrait of early 1960s Greenwich Village also emerges.

Many of the major players and personalities – Dave Van Ronk, Pete Seeger, Liam Clancy, the New Lost City Ramblers, Folklore Center proprietor Izzy Young – are seen in period photos and footage, as well as modern-day interviews reflecting on Mr. Dylan’s rise. But it’s left to an emaciated Allen Ginsberg to connect Mr. Dylan to another lineage: that of the Beat poets. When he first heard “A Hard Rain’s Gonna Fall,” Ginsberg says, he wept, knowing that the torch had been past from his generation to Mr. Dylan (if not Mr. Dylan’s generation).

Part 1 ends with Mr. Dylan’s triumphant appearance at the Newport Folk Festival in 1963. Already, he was emerging as the voice of his generation and the inheritor of the legacy of Woody and Mr. Seeger. The festival concludes with Mr. Dylan singing his song “Blowin’ in the Wind”- by then the unofficial anthem of the folk revival – backed by Mr. Seeger, Joan Baez, the Staples Singers, and Peter, Paul, and Mary, all interlocking hands. It’s a poignant moment, and a pregnant one – we know the unity won’t last.

The drama of Part 2 is watching Mr. Dylan chafe and buck under the constraints imposed upon him. The specifics of this aspect of the story – going electric at Newport ’65; the nightly clash with audiences during the whirlwind acoustic-electric tour of ’66; the “motorcycle crash” and ensuing seclusion – are well-known to Mr. Dylan’s fans, but are made vivid once more with never-before-seen footage.

There’s a wonderful scene in which Mr. Dylan performs at the 1964 Newport Folk Festival’s Topical Song Workshop, the very heart of the protest song culture. But instead of singing something topical, he brashly belts out the kaleidoscopically opaque “Mr. Tambourine Man” while Mr. Seeger – the man responsible for the maxim “it’s how much good a song does, not how good it is, that matters” – looks on, nervously tapping his foot and holding his mouth in his hands. If he’d let it go, his jaw would have dropped.

The climactic 1966 tour lives up to its legend. Even as the crowd taunts and jeers him through his electric sets, Mr. Dylan taunts back; he gives as good as he gets. But for all his apparent piss and vinegar, it’s clear the nightly confrontation and the numerous drugs he’s using to cope are taking their toll. Backstage before one show, Mr. Dylan quips, “I’m gonna get a new Bob Dylan; we’ll see how long he lasts.” By the end, this one is worn out. In one of his final interviews, he looks like the walking dead; neither his bleary eyes nor his bedraggled mind can seem to focus.

Looking back from a distance of almost 40 years, however, the old spark returns. Describing his self-imposed exile after 1966 (he wouldn’t tour for the next eight years), Mr. Dylan says, “I’d had it with the whole scene.” When the off camera interviewer (not Mr. Scorsese) asks him to elaborate – what people? what scene? – he answers, “Well, people like you,” barely suppressing a devilish grin.

“No Direction Home” will be released on DVD September 20 and will air on PBS September 26 and 27.