In a busy museum, unknown to the visitors and tour groups, something wonderful was about to happen. It began with a single cellist who sat by himself at the grand lobby of the National Air and Space Museum’s “Milestones of Flight” gallery.

One by one, members of the U.S. Air Force Band took their places, led by Col. Larry H. Lang, the commander and conductor of the band. The theme was the same: the musicians were wearing coats which they would take off and hand to another soldier.

The informal arrangement of band members soon appeared on the floor, with musicians bringing various orchestra instruments with them or being handed their instruments by another soldier.

It was amazing how they moved to their places, soon creating an organized arrangement akin to a military formation.

At the balcony, two women who first appeared to be museum patrons were filmed singing a few seconds later. Soon, a number of other choir members joined them at the balcony while the orchestra below continued playing.

There were also some musicians at the second floor balcony.

Watch the awesome performance of “Jesu, Joy of Man’s Desiring/Joy to the World” by the band and the singers here: