Disappearing pipe organ sound

This morning I was in my church when one artist from the Art Academy showed up together with the sound engineer. They wanted to record some special organ effects for our experimental project "Living Organ". They needed complete silence so we had to wait a while and even ask for custodians not to work for a while. At first we recorded the two pipes that comprise the Timpani stop and its vibrations. Then I played a couple of chords and then turned off the blower and kept holding the chord. They wanted to record the disappearance of organ sound. When they left I recorded this effect on my own on C Major chord. Enjoy!