Luc Sante at the New York Review of Books:
Then again, it could be said that historical fiction, like science fiction, is really always about the present. Llewyn Davis is a creature of the here and now, not of 1961. He has none of the communitarian goodwill, the erudite passion, or the optimistic idealism that marked the period. He is a confused, irascible striver who isn’t sure what he is striving for, apparently seeking a career when folk music was about the last place you’d look for one. It is suggested that he has been flopping on friends’ floors for months, when, at the time, people generally only did that when they first hit town, since it wasn’t hard to scratch up the twenty or thirty bucks a month it took to rent a tenement flat fifty years ago.
But if you excise the period details, he makes sense. Whereas in a better time he would spend five or ten years woodshedding and developing a soul, he has no choice but to enter some kind of race right away or die on the vine. He is consistently crass because he feels threatened by people and ideas he can’t dominate—and he can’t dominate very much because he feels threatened. (How else to explain his heckling an Appalachian singer, complete with autoharp and authentically awkward?) Somehow he has made a connection to something that is genuine and profound—the haunting music—but circumstances force him to treat it as a card to play rather than as a path to explore.