“Inside Llewyn Davis” is a new kind of project for the Coen brothers to take on. To an extent, the film is a musical of sorts along the lines of “Once.” In addition to being a love letter to old folk songs, it’s also one of the most brutally honest, if not disheartening, movies about the cruel nature of show business. While different territory for the masterful directing duo, “Inside Llewyn Davis” still has the Coen’s distinctive signature all over it. As with many of their films, they find the comedy in bleakness and the bleakness in comedy, resulting in a narrative that’s either saying a lot or saying nothing at all. However you view it, boy is it fascinating to watch.Set in Greenwich Village in 1961, the film focuses on a folk singer named Llewyn Davis, played by a dazed Oscar Isaac in a breakthrough performance. Ever since Llewyn’s musical partner committed suicide, he’s essentially been Garfunkel without Simon. His only possessions are his guitar, whatever he can carry in his one bag, and a cat he’s been forced to look after. If anyone has any idea what the cat is supposed to represent or if it’s supposed to represent anything, please let me know.Like the title character from “Frances Ha,” Llewyn doesn’t really have a home and must crash on friend’s couches/floors. Of course the closest thing Llewyn has to friends are two fellow singers named Jean (Carey Mulligan) and her husband Jim (Justin Timberlake). Mulligan particularly nails every second she’s on screen as an articulately aggressive shrew who’s fed up with Llewyn mooching off her family. Jean is only given more reason to loathe Llewyn after finding out she might be carrying his child.Not too long ago we got “Nebraska,” where Bruce Dern set out on a road trip to claim his final shot at glory. “Inside Llewyn Davis” is also very much a road trip movie with Llewyn searching for his purpose in life. He comes across a number of colorful characters along the way, including Adam Driver as a more successful performer, Stark Sands as an extremely earnest solider, and a hilarious John Goodman as a loudmouth on the verge of death. Where “Nebraska” had a clear destination and message, however, “Inside Llewyn Davis” is all over the map. Then again, so is the film’s main character. He has no idea what he’s doing, where he’s going, and pretty much ends up where he started.Llewyn Davis is actually very similar, yet also very different, to another Coen brother’s character, Jeffrey Lebowski aka The Dude. Both men are meandering bums that contribute nothing to society. When all is said and done, neither man learns anything, accomplishes anything, or goes through a life-altering change. The key difference is that The Dude’s completely content with just existing where Llewyn is desperate to find something to live for. The fact Llewyn has ambitions only makes it more tragic whenever he comes up with nothing. He’s a sad, but true, character that can resonate with any struggling artist out there.The covers of all the folk songs, a majority of which were performed live, are also splendidly tied into the story. The film does make room for one semi-original song called “Please Mr. Kennedy,” which the Coen’s developed with Timberlake and T Bone Burnett with some inspiration from George Cromarty and Ed Rush. It’s an inventive, catchy as hell little tune you’ll have a hard time getting out of your head. Too bad it was deemed ineligible for a Best Original Song nomination at the Oscars, but at least that will only make it easier for “Let it Go” from “Frozen” to take home the gold.