The landscape of American film has changed considerably in the 30 years since Joel and Ethan Coen announced themselves with their blackly comic neo-noir debut Blood Simple.

Once dismissively bracketed as ‘arthouse’, the Coens are among a handful of gifted filmmakers to have transformed the cinematic panorama without compromising their unique sensibility; to the extent their bleakly violent 2007 masterpiece No Country For Old Men won Best Film and Best Director Oscars and made a ton of money at the box office to boot.

With this, their 16th film, the Coens almost out-Coen themselves with a Russian doll of a movie that’s as enigmatic as it is engrossing.

The roster of seemingly cursed characters with a leaning towards self-destruction is a growing one in the Coens’ filmography and Llewyn Davis’ tractionless folk musician is right up there with Barton Fink, The Man Who Wasn’t There‘s Ed Crane Larry Gopnik from A Serious Man.

Llewyn (Oscar Isaac) is, like the songs he plays, “never new and never gets old” and spends his days drifting around New York’s early-60s Greenwich Village playing the odd gig and relying on the generosity of friends for a place to lay his head. You get the sense things have been this way since his former musical partner Mike committed suicide a few years earlier, while his only solo album, Inside Llewyn Davis, has fallen through the critical and commercial cracks.

His inertia has left him bitter, despite (or because of) it being almost entirely his own fault. Llewyn simply can’t fathom how or why the folk-by-numbers tunes of the innocuous Troy Nelson (Stark Sands) “connect with people” and can’t hide his derision when playing session guitar on the inane folk-pop pap Please Mr Kennedy (the film’s standout hilarious scene) written by his friend Jim (Justin Timberlake). Meanwhile, Jim and Llewyn’s ex-flame, the perennially angry Jean (Carey Mulligan), are also starting to make waves on the folk scene as a duet – another sign that he’s being left behind.

Opportunities present themselves, but Llewyn has a compulsion to snatch defeat from the jaws of something more prosperous. An audition for respected Chicago producer Bud Grossman (F. Murray Abraham) comes to naught when, instead of playing something catchy, Llewyn instead chooses the sombre ballad The Death Of Queen Jane. Grossman’s pithy summation “I don’t see a lot of money here” firstly reminds us why it’s called the music business, and secondly underscores the fact Llewyn’s always going to be a square box trying to fit in a round hole.

The Coens’ very best films open themselves up to multiple interpretations and Inside Llewyn Davis is no different. For me, the oppressive sense of death hangs over the film like a shroud, to the extent that it could be argued the world we see Llewyn wandering around is some kind of purgatory.

Bruno Delbonnel’s chilly cinematography lends the film a ghostly pallor, while the eerie road trip Llewyn takes with beat poet Johnny Five (Garrett Hedlund) and obnoxious Dr John-alike jazz muso Roland Turner (the one and only John Goodman) from New York to Chicago is like something out of a supernatural nightmare, with ominous-sounding vehicles screeching past their car.

Furthermore, the cat(s) that Llewyn cannot seem to escape from have long been regarded as a symbol of death, while the fact one of the cats is called Ulysses could be a reference to Tennyson’s celebrated poem of the same name (rather than James Joyce’s novel) about a man with the spectre of death hanging over him.

The songs Llewyn performs are also soaked in morbidity, from The Death Of Queen Jane, to Hang Me Oh Hang Me (“wouldn’t mind the hangin… but the layin in the grave so long”), while the film’s elliptical structure could be seen as purgatorial. Mind you, it just as easily be about a poor schmuck living day-to-day and who gets saddled with a cat. That’s the Coens for you.

Isaac gives a superlative performance as the downtrodden Llewyn, a curious figure who’s his own worst enemy but somehow illicits our sympathy. There’s something both maddening and admirable about his bloody-mindedness.

The Coens have been accused in the past of being unsympathetic towards their characters and it’s a charge that’s been levelled at Llewyn Davis. This is to miss the point, however. Llewyn is flawed, of that there is no doubt, but Isaac injects the character with real pathos.

It may be as difficult to pin down as its leading character, but Inside Llewyn Davis is achingly beautiful and melancholic and another masterpiece from the Coens.