The song is short, just one measure long. Usually set in six-eight time, its melody arcs in a single crescendo before landing on a long rest. While a skin drum rolls in the background, the lead instruments have the sharpness of a trumpet and the tone of an oboe. What vibrates is not a reed but the tiny space between the door and the frame, the sash and the sill, or even the cracks in the wall. Like the breath of the soloist, this invisible energy captivates the ears before traveling down the spine. It is nature’s warning; “take cover,” “hunker down,” “batten the hatches,” “man the sails.” Two air pressure systems–engaged fully at war–turn stillness to gust, silence to eery melody.