Zilker Tree Holiday Festival. You knew it as the Trail of Lights. This year's event, scaled back as the city deals with a budget crunch, is still free and will be built around the Zilker Tree. All the festivities will be on the Zilker Park grounds around the tree and the Zilker Hillside Theater, south of Barton Springs Road. The nine-day event, which includes light displays, concessions and nightly entertainment on two stages, opens Sunday and runs 6 to 10 p.m. nightly through Dec. 21. Parking is $10 a car this year (down from $15), and Barton Springs Road will be closed to through traffic from Stratford Lane to Robert E. Lee Road. Ray Benson and Asleep at the Wheel will play a free show on Dec. 21 at the park to close out the festival. In announcing the show, Benson said he's recruiting other musicians to join him at the concert, which also will feature a singalong to holiday carols. "Even if it's cold, we love to play," he said. The whole thing is expected to cost $374,000, down from the $1 million needed for the full Trail of Lights. If you're interested in sponsoring or volunteering, call the Parks Department at 974-6700.