WATCH: Air Force Academy a capella group performs on 'America's Got Talent' semifinals
In The Stairwell, the Air Force Academy a capella group, performed Ed Sheeran's hit "Castle On The Hill" on the semifinals of NBC's "America's Got Talent" Tuesday night.
Click here to vote to send the group to the finals. Voting ends at 5 a.m. Wednesday.
Results will be announced Wednesday night.