Col. Larry H. Lang, United States Air Force Band commander, thanks audience members after their flash mob at the Smithsonian National Air and Space Museum Udvar-Hazy Center in Chantilly, Va., Dec. 2, 2014. Approximately 160 band members played for museum spectators promoting their free, upcoming holiday concerts in the National Capital Region. (U.S. Air Force photo/Senior Airman Nesha Humes)