The Coen brothers have made a movie about a self-important, obnoxious bum who sponges off people because he believes he was meant for better things than holding down a job. But such a movie, without any frills, would immediately be dismissed as irritating and boring. And so it needs some frills.
First, they decided to make this bum a folk singer. They had previously made the movie O Brother Where Art Thou? (2000), which succeeded with people that liked the music, although it failed miserably with anyone that did not. So maybe they figured this movie would appeal to people that like folk music. And even if the folk music in the movie is pretty bad, at least as far as the music performed by the title character is concerned, we know we are supposed to overlook the fact that he is a self-important, obnoxious bum because he is an artist, and that means we are supposed to care.
Frill number two is a cat. Having a cat continually appear and then disappear gives the movie a motif, making it appear that there is some deeper, hidden meaning to it all. There isn’t, but something has to get this movie on its legs. The cat eventually turns out to have the name Ulysses. Gosh, you mean the return of the cat is like the return of Ulysses? Well, telling a dumb story with parallels to The Odyssey worked for James Joyce, so maybe the Coen brothers figured it would work for them too. And it recalls the main character in the movie O Brother Where Art Thou? So make that two dumb movies by the Coen brothers that are supposed to be spiced up somehow by alluding Homer’s epic, with the second one also alluding to the first.
Finally, there is a time loop. Sort of. Except that in the second iteration of the time loop, the cat does not get away. Now, there are some pretty good time loop movies. Dead of Night (1945) was the first movie I know of to try this, and it worked fairly well. And, of course, the greatest such movie is Groundhog Day (1993). But does a time loop belong in a movie about a folk singer? I mean, some genres don’t really mix well. It’s like a movie that starts out as a murder mystery, and halfway through, while we are trying to figure out who done it, Godzilla comes to town. However, the Coen brothers were desperate for another frill to keep this movie from seeming to be what it really is, and so a time loop is what we get.