It’s a fair night over at TCM, where a couple of prime-time movies are presented that have to do with world’s fairs. 1944’s Meet Me in St. Louis is a period piece starring Judy Garland, and directed by her husband, Vincente Minnelli. It’s set in the year before St. Louis hosted the 1904 World’s Fair, and tracks the events leading up to it, as seen by a regular St. Louis family. This musical is the source for both “The Trolley Song” and “Have Yourself a Merry Little Christmas.”