Age tends not to be a problem when you've always looked elderly and addled. Professor Irwin Corey, who turned 91 this year, was particularly popular in the 60s and early 70s, when trickster iconoclasts were especially prized, but honed his craft in the 30s and 40s, a chaotic time when vaudeville was dying and no one quite knew what was coming next. That's when he developed his trademarks: adopting a brilliant but scatterbrained persona ("the world's foremost authority"), he'd begin with some physical shtick, then deliver a long, insanely digressive lecture that always began with the word "however." Filled with unexpected highbrow and lowbrow cultural references, Corey's ad-libbed stream-of-consciousness monologues could create a kind of pure Zen comedy. Some of his gems have become part of the popular culture: "Wherever you go, there you are" (borrowed by Buckaroo Banzai), "You can get further with a kind word and a gun than you can with just a kind word" (often attributed to Al Capone), and "If we don't change direction soon, we'll end up where we're going." Sort of a missing link between Lord Buckley and Lenny Bruce, Corey outlived them both and became a link between Bruce and performers like Eric Bogosian and Danny Hoch. To celebrate the opening of Prop Thtr's New Plays 2005 festival, Corey performs with Paula Killen, Kestutis Nakas, and others. 7/8-7/10: Fri-Sat 10:30 PM, Sun noon. Prop Thtr, 3502-4 N. Elston, 773-539-7838. $20.