The talented men of In The Stairwell are all members of the United States Air Force. They started singing in the stairwells, as freshmen were not allowed to sing in the dorms, and now they're trying to win big on America's Got Talent. These incredible servicemen are giving it their all with an a cappella rendition of 'Drag Me Down.' I just love hearing all these harmonies come together to make such a beautiful sound.