Near the end of Inside Llewyn Davis, the titular hero (Oscar Isaac)—a struggling folk singer in 1961 Greenwich Village—tears into a version of a song we’ve already heard a couple of times before, the folk standard “Fare Thee Well.” It’s a raw, blistering rendition, occupying a strange place in the film’s fragmented chronology—and it just might be the key to unlocking another masterful creation by Joel and Ethan Coen, one that may be the most poignant and human story they’ve ever created.

Like many Coen brothers’ films, this one is a kind of odyssey—and a more literally Homeric one than anything outside of O Brother, Where Art Thou? From an opening that finds Llewyn being beaten in an alley as comeuppance for some unspecified offense, the Coens flash back several days, following the itinerant, homeless Llewyn as he bounces from couch to couch and seems to give offense to everyone he knows. He accidentally lets out the cat of an uptown benefactor; he may have impregnated Jean (Carey Mulligan), the wife of his musician friend Jim (Justin Timberlake); a visit to his sister (Jeanine Serralles) finds him insulting more conventional lifestyle choices than his own. That Llewyn, he’s not an easy fellow to embrace. Or to put it more simply: He’s kind of a dick.

But as the Coens gradually parcel out information, the character gets more and more complicated. Yes, he’s the kind of self-righteous artist who snorts at Jim and Jean’s “careerist” aspirations and the lyrics of the novelty song Jim has written (the hilarious “Please Mr. Kennedy”). Yet he also recently went solo, for reasons not immediately clear after working with a partner named Mike. He discovers, when setting up an appointment for Jean to have an abortion, that a previous partner actually carried his baby to term.

And Llewyn’s relationship with his father—and dad’s career as a merchant seaman—is complicated by present circumstances as well. Isaac’s performance is wonderfully nuanced, but it is particularly during the song performances that he reveals the Coens’ grand purpose in Inside Llewyn Davis: They’re exploring grief, and how easy it is not to confront it.

Because the Coens have always been masters of moments—tense, intricate set pieces, or memorable bursts of dialogue—it’s been easy over the years to dismiss them as chilly technicians who turn to humanism as a last resort. There’s a terrific extended sequence in Llewyn Davis that finds Llewyn sharing a road trip to Chicago with a heroin-addicted jazz musician (John Goodman) and his taciturn driver (Garrett Hedlund), and at times it feels like it might be little more than a showcase for Goodman’s blowhard performance.

Then, that road trip reaches its climactic moment—Llewyn’s audition for the owner (F. Murray Abraham) of a legendary Chicago folk-music club—and a cruel punch line also serves as turning point for Llewyn starting, ever so gradually, to let things go.

If Inside Llewyn Davis were nothing but its superficial pleasures, it would still be one of the year’s best films. Bruno Delbonnel’s cinematography washes music venues in cool blues, and the exteriors in the muted tones of a chilly New York winter. Every performance—the remarkable Isaac and Goodman, but also Mulligan’s venom-spewing Jean—hits a note somewhere beyond the stylized bits so often associated with Coen brothers films. And there’s all that music, lovely and haunting traditional folk melodies filled with yearning for something that seems impossible or out of reach.

That’s why it’s no mere elaborate exercise in style that the Coens chose this milieu for Llewyn’s story. As he brings a ferocious emotion to that final performance of “Fare Thee Well”—one that we don’t see when the film opens on the events of that same evening—we’re finally getting a glimpse at a Llewyn Davis ready to move on from the unresolved issues that hold him back from any chance at getting out of his own self-destructive way.

Inside Llewyn Davis may be just as funny and vividly drawn as other Coen brothers films, but it’s also a heartbreaking look at its title character finally getting those things that are inside Llewyn Davis out, so that he can, at last, say “au revoir.”

INSIDE LLEWYN DAVIS

Oscar Isaac, Carey Mulligan, John Goodman
Rated R

Twitter: @ScottRenshaw