A devastating indictment of race relations in the Upper Midwest is currently playing at a theater in the Twin Cities. “The Last Minstrel Show,” which details (and satirizes in explicit form) the lynching of three black men in Duluth, is hard to watch and even harder to analyze, and apparently, Minnesotans don’t want to hear it. The show is closing after only two weeks, due to abysmal ticket sales in a city that normally embraces theater of all types. “If virtually no one attends a play about an event virtually no one wants to talk about, then, as the show’s final production number asserts with nonchalant gaiety, ‘Nothing happened.’ Right? Isn’t that where we’re at societywise on the whole race issue?”