Seriously, though, the clip is from a movie called "Inside Llewyn Davis" which is loosely based on the career of Dave Von Ronk, one of the folk gurus of Greenwich Village. Van Ronk may not have gotten much fame in his own time, but his influence among other musicians at the time cannot be denied. Joni Mitchell often said that Van Ronk's rendition of "Both Sides Now" was the finest she'd ever heard. And Bob Dylan heaped praise on Van Ronk, saying "I'd heard Van Ronk back in the Midwest on records and thought he was pretty great, copied some of his recordings phrase for phrase. Van Ronk could howl and whisper, turn blues into ballads and ballads into blues. I loved his style. He was what the city was all about. In Greenwich Village, Van Ronk was king of the street, he reigned supreme."
The movie, Inside Llewyn Davis works very well as a Cohen Brothers concept, and as a primer for the kind of music that Dave Van Ronk played. However, if you're looking to get some insight into what kind of person Van Ronk was, Inside Llewyn Davis will disappoint. The movie, while incorporating some anecdotes from Van Ronk's life, portrays Llewyn Davis as an intelligent, arrogant asshole caught in a sisyphean cycle. Dave Van Ronk himself was a much different person. To truly get a feel for what he was like, check out his memoirs, "The Mayor Of MacDougal Street". It's worth a read.