|Not the laff riot you've been led to expect.
Why haven't I seen reviews that talk about the kinda-prominent supernatural/horror angle of Inside Llewyn Davis? No, I'm not kidding and, no, this isn't really much of a spoiler: you have the sense that something is up from practically the first scene.
Entertainment Weekly seems to dance around the issue with its review, using words like "spooky" and "hauntingly." And there are certainly readings of the Coen brothers film that don't require invoking "horror" as I just did, but ... man, it's right there. At the beginning, in the middle, at the end.
If, as I was, you're putting off the film because folk music isn't your thing, give it a second thought.