Most of the featured artists had to sit in a chair once they wobbled their way to the spotlight at center stage. Some talked about their strokes, a bad leg, or arthritis. But once the music began on this rainy September afternoon, all journeyed back to a time when, as Classie Ballou put it, they all had “29- or 30-inch waists.”

These were the Excello Reunion of All-Star Swamp ...