It's ''us'' against ''them'' in Houston native Bruce Norris's 2011 Pulitzer Prize-winning play Clybourne Park, but the ''us'' and the ''them''change with the times. Set in the same Chicago locale as the 1959 play A Raisin in the Sun, Clybourne Park follows two generations and their reaction to a change in their community's racial makeup. First, a black family moves into a white neighborhood in the 1950s, sparking all sorts of reactions. Fifty years later, the neighborhood is black and a white family moving in is the cause for concern. The New York Times called the show ''a spiky and insightful new comedy,'' while The New Yorker said it was ''superb, elegantly written, and hilarious.'' Poignant and provocative, Clybourne Park means to make audiences laugh and think at the same time.