Organ stop Pizza

Last year we went to Organ stop Pizza and enjoyed the music there. Went back last evening with the Farnsworths' and enjoyed it again. Huge organ is in a building. We stepped outisde and looked through a window where the air compressors are at(they generate thousands of foot pounds of air to this massive organ, it's run by 3 generators that put out huge amounts of power. I don't understand all how it works but I do know there's a lot of energy spent there making that sucker play the beautiful music.