The latest HeadCheese sketch revue is in a variety show style reminiscent of Monty Python. Silent interludes and songs alternate with a hodgepodge of wisecracking scenes about historical and current events, gender differences, and contemporary culture. Not all the material is fresh--Tyler Bohne and Patrick Zielinski's "British Insult Theatre" was done years ago, and got bigger laughs then--and some scenes (particularly the final one) fall flat. Yet this quick-paced hour-long show, written and performed by an ensemble of seven, is often sharp-witted. Best are bits about a man calling a grizzly bear chat line, Enlightenment knocking at the door of an uninterested Dark Ages, and medieval players trying to drum up audience participation in an improvisation. Through 10/30: Mon 8 PM, Apollo Theater, studio, 2540 N. Lincoln, 773-935-6100, $11, $1 off with donation of nonperishable food item.