Tasteful humor is hardly Sweetback Productions' stock-in-trade. But this time around its annual holiday revue (made up of selections from 12 sketches, monologues, and songs), created jointly with Chemically Imbalanced Comedy, is noticeably smarter. Oh, adolescent sniggers could still be heard on the night I attended, and Paul Baio's dirty old Santa, Greg Landgraf's homeland-security Santa, and Chris Churchill's space-age Santa are generic parodies. But Sweetback founder Kelly Anchors tells a wistful tale about Barbie and the Lockerbie airline disaster, Jill Erickson makes Paige McLemore's parable about getting what you wish for poignant, and Angela McMahon's advice guru doggedly extends gentle comfort to the audience--even the two beer-swilling grinches bereft of seasonal cheer though December had yet to begin. Through 12/17: Fri 11 PM. $8. Then Fri 12/31, 8 PM. $25 ($40 per couple); includes postshow party. Cornservatory, 4210 N. Lincoln, 773-865-7731.