‘A Mighty Wind’ was another of those Christopher Guest mockumentaries that squandered talented actors on loser characters. The folk singing duo Mitch and Mickey (Eugene Levy and Catherine O’Hara) include their Civil War Romeo and Juliet tale “The Ballad of Bobby and June.” Their stars are crossed by the draft, though the poor Reb makes it home for Xmas with a hole in his chest. Gratuitous holidayism, but we’ll allow it. [Included is a church-set cover by Brandon Boring with Kayla Cardenas–see, this is what i’m: the satire is so serious no one gets it.]