Inside Llewyn Davis is not catchy, it does not have any memorable scene or even a song that it is going to remind you to that film, even though Isaac's voice and songs really touch your soul. We could say that this is a 1960's (2013's) version of Charlie Chaplin's The Kid (1921) because it talks about the dark side of the american dream. Between the two movies there are a lot of differences, more than things they could have in common but the american dream is one of those similarities.
Joel and Ethan Coen, take Llewyn Davis, a kind of Ulises (Oscarr Isaac) from the Greek mythology, into a one week journey where he has to face obstacles, is helped by people he knows and other's he does not know, just like Ulises did when he was navigating. Davis is navigating in America, looking for an opportunity to become a successful musician. The poetry of this movie is the atmosphere created by the directors and crew that submerge you into a dark place in the deepness of the ocean, with no hope, no feelings towards anybody.... lost like a cat looking for another live, so that he can start again.
Isaac really nails his part but it is a movie that does not have dialogues, or at least, remarkable dialogues... it is just about listening to music and feeling the darkness of failure. With that being said all I can add is that it is an odd movie, that you would recommend because it is a good story but that you would not recommend to some people because it is a very different cinematography from the one we're used to. Very poetic, very deep, but with no references - you just need to sit and let the film enter to your soul, slowly like a poem.