Master Sgt. Joseph Haughton and Tech. Sgt. Mandi Harper perform during a concert featuring the U.S. Air Force Band’s Concert Band and Singing Sergeants at the College of DuPage in Glen Ellyn, Ill, April 4, 2014. Haughton, a native of Philadelphia, is a tenor vocalist. Harper, a native of Columbus, Ohio, is a soprano vocalist. (U.S. Air Force photo/Master Sgt. Tammie Moore)