CMA Country Christmas, a two-hour music celebration, will air on ABC on Dec. 3. Hosted by Trisha Yearwood, this year’s festive showcase was taped on Sept. 25 at Belmont University’s Curb Event Center in Nashville. A number of stars took the stage to sing their favorite yuletide tunes, including Trisha, Dierks Bentley, Runaway June, Kristin…