When the town of Blaine, Missouri approaches its sesquicentennial, there’s only one way to celebrate: with a musical revue called “Red, White and Blaine.” Hoping the show will be his ticket back to Broadway, impresario Corky St. Clair (Christopher Guest) rounds up a cast of enthusiastic but untalented locals (Eugene Levy, Fred Willard, Catherine O’Hara, and Parker Posey) to perform his masterwork; and when Corky reveals that theater agent Mort Guffman will attend the opening, things really kick into high gear.