The Big Bang, Chicago Theatre Downstairs, through Aug. 20. A snazzy new 250-seat room hosts this musical comedy history of the world. The humor—from the old-fashioned Catskills school of funny wigs and funny accents—is remarkably obscenity-free. MSB
Imagine Tap, Harris Theater, through Aug. 6. A smokin' band and dazzling dancers—influenced by Gregory Hines, Savion Glover, Hip Hop and breakdance—in a new revue with hopes for a New York future. Brilliant tap, but non-dance bits still need work. JA
Julius Caesar, Festival Theatre ( Oak Park ) through Aug. 15. Sweat with Rome's military men as they plot to frag their commander-in-chief. Paul Perroni makes 'lean and hungry' Cassius a candidate for his own action figure—or at least a role on The Unit. MSB
The Unmentionables, Steppenwolf, through Aug. 27. Author Bruce Norris takes the plot devices of farce and twists them to the dark side in his bleak comedy about principles falling to expediency, in which all—even the viewers—are implicated. First rate acting. JA
—By Abarbanel and Barnidge