Inside Llewyn Davis begins with its titular character (played by Oscar Isaac), a folk singer in 1961 Greenwich Village, wrapping up a gig at a small venue. After he finishes his lovely take on a mundane old folk tune, he's told to go outside where a "friend" is waiting. This "friend" turns out to be a mysterious stranger in a suit, who suddenly beats up our hero, then storms away.
This scene is a Coen Brothers trope: the schlubby antihero getting the stuffing kicked out of him as a snarky message from a degenerate universe. But Inside Llewyn Davis is a different creature. Instead of the now-standard Coen shtick, with the confident naif becoming exposed to the lowest depths of human behavior (which had mostly run its course by A Serious Man and True Grit), Llewyn's own odyssey inverts this, so that the lonely singer is instead shown the sadness, desperation, and even love hidden behind sometimes cruel words.
With the Coens' usual manic sadism replaced by a distinct melancholy, for once I get a sense that they're not laughing at their protagonist. They may even be eulogizing him: as a talented but not particularly special folk singer, Llewyn is – not unsympathetically – depicted as just another hungry contender in a crowded field. The irony here, that the success these singers fight for would soon be obliterated by a newcomer named Bob Dylan, isn't lost on the Coens. But instead of the joke being on Llewyn Davis, the character seems aware of the fleeting nature of his own dreams.
Despite the emotional distinction from the rest of the Coens' oeuvre (with the possible exception of The Man Who Wasn't There), the presence of a cute cat, and French cinematographer Bruno Delbonnel replacing the Coens' usual DP Roger Deakins (providing a muted palette reportedly inspired by the cover of The Freewheelin' Bob Dylan), this is still every bit a Coen Brothers movie: you've got the snappy dialogue, the colorful supporting characters, the directors' obsessive attention to period detail, and a certain inscrutability.
I have to admit that I did get a little bored while watching Inside Llewyn Davis. The folk song scenes can drag, and the story is in no hurry to get anywhere. However, I would up haunted by the film for several days on. That's enough for me to recommend it. There's a lot lurking here under the surface, and in a rare moment of generosity, the Coens seem to invite us to find it.