Here's what's going on today (Saturday, Dec. 15): The Performing Arts Collective of Savannah's annual musical production of Langston Hughes' Black Nativity is onstage at 7 p.m. at Fresh Fire from Heaven Christian Church, on Bull Street. National Lampoon's Christmas Vacation screens at the Trustees Theater at 7. In the clubs: Bear Fight! Returns to the Jinx, with Hot Plate and Crazy Bag Lady, the Talking Heads tribute Same As It Ever Was is at Live Wire, the Holy Ghosts are at the Sparetime, and Each & Every Opus shares a Wormhole bill with Paleface.