LANHAM, Md. (CBSDC) — The U.S. Air Force Band engaged in a little guerilla advertising Tuesday, as 120 members treated visitors to the Smithsonian’s National Air and Space Museum to a surprise performance.

It was the first flash mob to be produced by one of the five military branches’ top bands.

The four-minute performance began with just one cellist in the “Milestones of Flight” gallery. Gradually, instrumentalists streamed into the room and appeared from behind airplanes and space capsules. Vocalists chimed in from the museum’s second-floor balcony.

They performed an original arrangement of Jesu, Joy of Man’s Desiring/Joy to the World led by the band’s commander Col. Larry H. Lang.

The flash mob kicked off the band’s holiday performance season, which includes 29 concerts throughout the D.C. area.