The Great Space Organ is a piece of technology known as an extrauniversal control module. It uses its pipes (of which there are so many that the organ can produce virtually any sound. It uses sound to control elements of the big bang). Mostly, it uses Beethoven's 7th Symphony, Movement II to make entire planets unstable, usually resulting in an incredible explosion. The Great Space Organ is very large; it is about 2000 feet in height, and other dimensions are likewise. On one side, there is the keyboard and stops, encased in glass, except that they are facing away from the organ. There is also a steering wheel there. Inside, there are several rooms, including Engineering, Lounge, Master Bedroom, O Hovenbeet Room, I Hate The Big Bang Room, Room, Bathroom, The Great Safe of the MEUSM Things, The Closet, and the BunnyMig room.
At some point, Hovenbeet crashed the organ on Earth. He spent many years rebuilding it, and created a launchpad for it. The launch created an enormous explosion, destroying most of the launch pad. What remains is now called stonehenge.