The US Air Force Staged a Beautiful Flash Mob at a Museum 26.63K Gabrielle Bluestone 12/08/13 07:37PM Filed to: Flash Mobs Flash Mobs Orchestra Band Normally flash mobs are pretty annoying for anyone who's not involved in them. But the United States Air Force Band became the exception to the rule with a pretty sweet impromptu concert at the National Air and Space Museum on Tuesday.[h/t NPR]