As predicted, the music was excellent -- I think the casting call went to musicians, not actors. The plot, if you can call it that, was so-so. It described a legendary meeting of Johnny Cash, Carl Perkins, Elvis Presley, and Jerry Lee Lewis, so as you might expect, most of the people in the audience were senior citizens.
The American South is a remarkable place, sometimes associated (incorrectly, I think) with backwardness and poverty, but it's also at the core of America, as you can see from the contributions Southerners have made to American culture with Jazz, Blues, Rock N Roll, not to mention most of our post-War U.S. Presidents. People from the Coasts, or foreigners: if you want to really understand America, you need to understand the South.