A review from The Movie Snob:

A Mighty Wind. (A-) If you have seen This is Spinal Tap or Waiting for Guffman or Best in Show, all I can say is that this movie is more of the same. Same actors, same "mockumentary" shtick, different focus. This time the folk-music scene comes in for some good-natured ribbing, and I thought the result was very funny. When a leading producer of folk music passes away, his son tries to organize a memorial concert featuring three leading folk-music acts from the 60's, two of which have long since split up. Interviews with the various musicians are interspersed in the main story of how the concert ultimately comes together. I thought this one was quite a bit better than Best in Show and suffered only because the director tries to give virtually equal time to every member of the huge cast. Spinal Tap and Guffman benefited from a tighter focus on a smaller group of castmembers.