Brilliantly contrasting old with new, Center Theatre Group places one of David Mamet's earliest works alongside his latest production. In the classic Duck Variations, two geezers wax poetic, albeit in a rapid-fire theatrical rhythm, about the philosophical underpinnings of existence. The farcical premiere, Keep Your Pantheon, on the other hand, follows the fortunes and follies of a down-and-out acting troupe in ancient Rome. Mamet endows his characters with a sharply focused sense of wordplay, punctuated by a coarse and oftentimes delightfully abusive tone, so expect an entertaining view of one of this country's most compelling and controversial playwrights.