A Mighty Wind

The 2003 film A Mighty Wind was written by Christopher Guest and Eugene Levy, which gives you some idea of what you're in for. They also star in it, along with Michael McKean, Harry Shearer, Catherine O'Hara, and the other usual suspects. It's sort of like giving the Spinal Tap treatment to the folk band revival of the 1960s, although it wasn't such a big hit because the humor is more subtle and that era is not quite as relatable as that of This Is Spinal Tap.