Chicago can be a brutal testing ground for start-up dance companies, which have to struggle to find performance space and grab publicity. But the odds didn't buckle the well-oiled knees of the River North Dance Company. This talented jazz dance ensemble performs programs of short, Broadway-style numbers by established and emerging choreographers. They perform periodically at the Harris Theater for Music and Dance, but you never know where they'll pop up next; check their website or call for information on upcoming shows.