“A Complete Unknown” certainly lives up to its title.

You are hardly closer to understanding the soul of Bob Dylan after watching more than two hours of this moody look at America’s most enigmatic troubadour. But that’s not the point of James Mangold’s biopic: It’s not who Dylan is but what he does to us.

Mangold — who directed and co-wrote the screenplay with Jay Cocks — doesn’t do a traditional cradle-to-the-near-grave treatment. He concentrates on the few crucial years between when Dylan arrived in New York in 1961 and when he blew the doors off the Newport Folk Festival in 1965 by adding a Fender Stratocaster.

That means we never learn anything about Dylan before he arrives in Manhattan’s Greenwich Village with a guitar, a bomber jacket, a fisherman’s cap and ambition. And Dylan being Dylan, we just get scraps after that.

The world spins around him, this uber-cypher of American song. Women fall in love with him, musicians seek his orbit, record executives fight over his signature. The Cuban Missile Crisis melds into the Kennedy assassination and the March on Washington. What does Dylan make of all this? The answer is blowing in the wind.

Any sane actor would run away from this assignment. Not Timothée Chalamet, and “A Complete Unknown” is his most ambitious work to date, asking him not only to play insecure-within-a-sneer but also to play and sing 40 songs in Dylan’s unmistakable growl, complete with blustery harmonica.

The last big non- documentary attempt to understand Dylan was Todd Haynes’ “I’m Not There,” which split the assignment among seven actors. Chalamet does it all, moving from callow, fresh-faced songsmith to arrogant, selfish New Yorker to jaded, staggering pop star to Angry Young Man. There are moments when Chalamet tilts his head down and looks at the world slyly. There are others when the resemblance is uncanny, but also moments when it is forced. But you cannot deny he’s got the essence of Dylan.

The movie is adapted from Elijah Wald’s book “Dylan Goes Electric! Newport, Seeger, Dylan, and the Night That Split the Sixties.” Dylan isn’t a producer but did consult on the script.

It’s not the most glowing profile, though the sheer brilliance of the songs shows Dylan’s undeniable genius. Chalamet’s Dylan is unfaithful and jealous. The movie suggests that adding electric guitar at Newport in ’65 was less a brave stand for music’s evolution than a middle finger to anyone who dared put him in a box.

“A Complete Unknown” uses some of the DNA from “I’m Not There.” The best clues to what’s going on behind Dylan’s shades are the refracted light from others, like Joan Baez, Johnny Cash, Woody Guthrie, Pete Seeger and a girlfriend called Sylvie Russo, based on Dylan’s ex Suze Rotolo, who is pictured on 1963’s album cover for “The Freewheelin’ Bob Dylan.”

Edward Norton is a hangdog Seeger hoping to harness Dylan for the goodness of folk. Monica Barbaro is a revelation as Baez, Dylan’s on-again-off-again paramour. Boyd Holbrook is a sharklike, disrupting Cash, with the movie’s best line: “Make some noise, B.D. Track some mud on the carpet.” And Elle Fanning is captivating as Russo.

There are points to quibble — Dylan never faced a shout of “Judas!” from an enraged folkie at Newport; that came a year later in Manchester — but “A Complete Unknown” is utterly fascinating, capturing a moment in time when songs had weight, when they could move the culture — even if the singer who made them was as puzzling as a rolling stone.

MPA rating: R (for language)

Running time: 2:21

How to watch: In theaters