The “Guffman” of the title is Mort, a Broadway producer who fails to show up for the premiere of the original musical Red, White and Blaine, in small-town Blaine, Mo. Christopher Guest and Eugene Levy’s satire of community theater, and the mounting of a show from soup to nuts, is both devastatingly spot-on and heartfelt, with characters whose passion (for them, the play is really the thing) keeps the comedy of the film from devolving into ridicule. The leader is Corky St. Claire (Guest), a failed New York actor who actually believes he can stage a comeback from this small outpost of Middle America. And yet something genuine emerges: The well-executed mounting of an awful musical. As in subsequent films like Best in Show and A Mighty Wind, Guest and Levy outlined the script and trusted a company of seriously gifted comedic actors to take it from there. They did.