WASHINGTON -

The National Air and Space Museum is already an amazing experience for families. For some visitors, that experience was greatly enhanced thanks to a military flash mob.

The U.S. Air Force band surprised guests at the museum with a holiday-themed flash mob.

The performance started with a single cellist walking out to a chair in the middle of a crowd. Moments after he began to play, guests started seeing more band members walking out.

From tubas players to french horns players to saxophonists and bassoonists, musicians continued to join the group on the ground level.

Suddenly, two members began to sing from the second floor.

Eventually, the full concert band and "Singing Sergeants" gathered to perform a resounding rendition of "Joy to the World."