Altar Boyz” is still running at Swift Creek Mill Theatre, but there’s more going on there through the end of May: “Blues in the Night” is on stage when the Boyz are off. This is the 1980 Sheldon Epps revue with a cast of four covering more than two dozen blues songs, some more classic than others. We’re talking Bessie Smith blues, not Muddy Waters blues—sometimes brassy and bawdy, sometimes forlorn. Epps includes some interesting out-of-the box choices, too: Ann Ronel’s “Willow Weep for Me” and a haunting slow version of the jazz standard “Stompin’ at the Savoy.“