The Coen brothers return to the London Film Festival this year with the barnstorming Inside Llewyn Davis (2013), a picaresque odyssey following the close-calls and mishaps of an also-ran folk songster within the New York Greenwich Village scene. It’s the early sixties, well before Bob Dylan, Phil Ochs and Peter, Paul and Mary, and folk singer Llewyn Davis (Oscar Isaac, who also recorded his own tracks for the film) is waiting for his big break. It’s winter in New York and his adventures are both comically trivial – he loses a friend’s cat – and potentially dramatic – as he’s just got his friend’s wife, Jean (Carey Mulligan), pregnant.

Staring at the big success-shaped hole called failure, Llewyn snatches at the opportunity of a trip to Chicago where he may be able to persuade some big-time impresario to back him after the loss of the other half of his duo. Davis is a typical Coen anti-hero in that he’s otherwise so atypical. He behaves despicably until his attitude almost becomes admirable. Llewyn, seemingly relegated to the couch of life, is a man who has the selfishness of ambition linked to the misanthropy of slowly emerging despair. Everything is against our protagonist and while the audience might bay for a rags to riches trajectory, with setbacks only a temporary prelude to inevitable success, the Coens have created a magnificent paean to falling short.

This is essentially the film version of the Dylan autobiography Chronicles, the chapter Bob Dylan would have wrote if he’d remained Robert Zimmerman. The period detail is well-realised, without being finicky: the cars are dirty, there’s litter and lived in spaces, smoky clubs and brightly-lit diners. Following the departure of Roger Deakins, Bruno Delbonnel keeps standards consistently high. Elsewhere, the cameos by John Goodman, F. Murray Abraham, Justin Timberlake and a wonderful Garrett Hedlund – riffing on his recent turn in On the Road – are all separate delights.

However, Isaac will rightly win the most plaudits for a character to rank alongside Fink and ‘The Dude’ – dislikeable, at times just plain nasty, but never uninteresting. The music is also central, dominating the film and like O Brother Where Art Thou? (2000) comes as part of a collaboration with T. Bone Burnett. Its use sums up in its balancing act the delicate edge that the film as a whole traverses. There’s out-and-out parody here, but also a tangible sense of beauty; a romantic irony that says, “I’m joking but, you know, not really.” After the so-so generic experiment of True Grit (2011), Inside Llewyn Davis is an unmistakable return to top form for the brothers Coen.