We're almost to the top of Christmas mountain, which means we should hunker down for the night and conserve energy before the final ascent. There's no better place to recharge than in the joyous company of the annual Bach Society of St. Louis Christmas Candlelight concert. A family favorite since 1951, the performance features carols and the now-traditional candlelight procession through the hall. But because you've been good, you get a special treat: Our beloved Christine Brewer will perform "The Announcement of Christ's Birth" from Handel's Messiah as well as the sublime "O Holy Night." The program starts at 7:30 p.m. tonight at Powell Hall (718 North Grand Boulevard; 314-534-1700 or www.bachsociety.org). Tickets are $30 to $75.