The pipes sprouted in parallel ranks from a broad flat box of compressed air. All of the pipes for a given note—but belonging to different stops—lined up with each other along one axis. All of the pipes for a given stop—but tuned at different pitches—lined up with each other along the other, perpendicular axis. Down there in the flat box of air, then, was a mechanism that got air to the right pipes at the right times. When a key or pedal was depressed, all of the pipes capable of sounding the corresponding note would speak, as long as their stops were pulled out.