Yes, the film is actually called "Walk Hard". I really did not see many connections to "folk" - although there is a funny scene about learning the blues. "A Mighty Wind" was more in tune with folk references than this one. The Cash biopic does seem to be the main source of inspiration, but if you watch closely you will see the other films - for instance, the scene about Dewey's brother is a spin on "Ray". As Dewey goes through various phases, there are elements of other bio films and rock stars.

Art, not to drift this thread too much, I do see your issues with Folk Alliance. It really is about the "business" of acoustic music. The reference to "show biz" conjurs up images of trying to create stars, and from what I see at Folk Alliance is an emphasis on making a living and smoothing out paths for those that wish to pursue the music in that direction. Granted, they have a lot of work to do toward perpetuating the traditional arts - but I think there are other organizations that can provide that direction.   It's not for everyone, but I don't think they are trying to encourage people to become the next Dewey Cox.