Baby Wants Candy--a tight troupe now famous for its improvised musicals--began about seven years ago as one of the dozens of ImprovOlympic teams formed every year. Somehow they've avoided the usual dissolution of such groups. More impressive, they've never experienced the artistic conservatism that paralyzes improvisers eager to "do it right"--and reap the reward, presumably, of a career in NYC or LA. Instead the troupe has become the very model of smart, physical, quick-thinking, and just plain silly long-form improvisers. As evidenced by their 1,000th performance last weekend, they still play well together and manage to entertain. Inspired by the improbable suggestion "So this is it," nine actors (backed by the five-member Yes Band) improvised a complicated, hilarious, tongue-in-cheek tale of three partnerships on the rocks--two marriages and a professional relationship--and the narrator who helps bring the couples back together. Open run: Fri 10:30 PM. ImprovOlympic, 3541 N. Clark, 773-880-0199. $14.