The sardonic art of Ethan and Joel Coen, so scornful of their own surly and defeated characters, never has had much room for emotional depth. It extracts half-smiles and laughs, unease, sigh-inducing uplifts perhaps, but hardly ever tears. In that sense, what their new film Inside Llewyn Davis, about a gifted folk musician’s tragic search for recognition and lost parts of himself, does, is a wonderful revelation. It has so much feeling and warmth, that it almost feels like the brothers are now looking more directly inward, and going for a full shot of the unmitigated tragic rather than making wit and irony the point of a story. Irony is here too, and in plenty, but Inside Llewyn Davis is their saddest and most poetic story ever. The recognizable narrative style—wide sweeping shots with just one crucial thing or person moving somewhere in the frame, moving to overcharged close-ups—is complemented by the mood-inducing cinematography of Bruno Delbonnel.

The brothers have written a character they really seem to love—unlike most of their other leading men and women, who are oblique and often inarticulate studies in courage, brutality or psychosis. This eponymous hero (Oscar Isaac) alienates friends and lovers, disdains his talented and more articulate peers, and has a knack for outbursts of bitter rage in public—a dreadful person basically, whose former lover, also a singer (a barely effective Carrey Mulligan, paired opposite Justin Timberlake who, like the character she plays, has the role of an earnest, conforming singer) has nothing but eloquent spite for him. He is in penury and scurrying favours with friends he has betrayed, every night looking for a bed to sleep in. Yet it is impossible to hate Llewyn. At best, you laugh at his misadventures. With dishevelled, black hair, a tattered jacket and a muffler so 1960s, Llewyn is the damaged man some women love to fall in love with.

Llewyn comes alive when the spotlight is on. At New York’s Greenwich Village cafés—intimate in the 1960s, before Bob Dylan explodes on the scene and the fuss-free Village is unable to contain him—he sings folk songs about loss and idealism with an ashen, canorous voice. The music in the film, composed by T-Bone Burnett and sung by Isaac himself, is a powerful narrative tool—you know the marrow of Llewyn’s heart and mind, the way perhaps the writers know him and want us to know him, fleetingly while he is singing, but with lasting effect.

Isaac has certain key notes as the protagonist—a deadpan demeanour, and a gentleness punctuated by a mercurial temper. The scene in which he really reveals his character, all the while building up a sense of foreboding about his future, takes place in Chicago where he meets a studio executive Bud Grossman (F. Murray Abraham). Disbanded and far from his early fame with a partner who we get glimpses of through a record cover, this is Llewyn’s final attempt to convince the markets man that his art is worth the risk. In the snowy morning he reaches the studio, and waits, as the studio opens its windows and doors and sunlight cascades in. Faint guitar sounds float across. Finally, Llewlyn is sitting in front of the unamused executive, and singing all he has, with all he can muster. This is not music that would make money, he is told, and he leaves. It is a startlingly mature performance by Isaac, especially since the character has no surprises or redemptive moments.

New York in the 1960s is grey and a burnished brown. Llewyn is stuck with the pet cat of a generous friend. At a careless moment, the cat jumps out of a window. While fumbling through his stress and depression, Llewyn has suddenly found a purpose—he has to find the cat; as if he finds it, he will be absolved of all the wrongs of his past. Towards the end, when the animal is moving in subways and cars, stranded on highways, Llewyn holding him from running away, the lovely, restless creature becomes Llewyn himself. Whether he is finally safe and at home is tied to the end of Llewyn’s own journey.

The episode of Llewyn’s journey from New York to Chicago has the template of the best of Coen Brothers films—the quirky, the bizarre and the pathetic in one seamless whole. He braves a snowstorm, its pillage on him and the rickety car he drives, shown in suffocating close-ups, and takes a ride back, cat in tow, with a former jazz illuminary (the absolutely brilliant histrionics of John Goodman) who has lapsed into anonymity. An embittered and mean motormouth, he is a foil to Llewlyn, who is perhaps uncomfortable not only with jazz’s historic superiority over folk music, but with an old musician on the ebb. It is the most hilarious episode of the film, and yet most burdened by a sense of doom.

By the end, long after his physical journey is over, another huge test awaits Llewyn. We hear the creaky and raspy balladeer’s voice that would hold the world captive for years to come, as Llewyn comes out of the back door of the café where he sings. He meets a man waiting for combat. The end is not his defeat or doom or a chance at fame, because nothing really changes. The only point is Llewyn’s music and his malaise, the fidgety cat, and the realization that the Coen Brothers are so full of wonderful surprises.

Inside Llewyn Davis released in theatres on Friday