The United States Air Force Band performs a flash mob at the Smithsonian's National Air and Space Museum Washington, D.C., Dec. 3, 2013. The band conducted the flash mob to promote their upcoming holiday concerts at the Air and Space Museum Dec. 5th, 6th, and 7th. The concerts are free of charge and open to all. (U.S. Air Force photo by/ Airman 1st Class Nesha Humes)