No one in Sanctityville thinks legalizing gay marriage will make a difference to their little town, a straight and narrow place where "the women and dogs obey." That is, until the next morning, when the housewives start singing about the joys of armpit hair and carpet-munching; the once-upstanding doctor, now clad in bottomless chaps, laments melodically how "nobody wants a daddy who's a bottom"; and the townsmen turn the Elk's Lodge into a pleasure pit. For a single concept show, "The Day the World Went Queer" is sure amusing with infectiously raunchy lyrics and rowdy tunes (delivered by a snappy cast with goofy charm to spare). Yet even with sharp comic timing and vibrant voices, the premise wears thin over two hours, and after intermission, the play starts to sag, with some songs slipping from delirious to discordant. Apparently, even the best-intended marriages have a shelf-life nowadays.