How do church organs work?

Question

I walked into a hundred or so year old church the other day, and beside from being beautiful on all accounts, i saw series of pipes displayed all around the church, in the tops of the walls to the left and right of the main seating area, in walls of seperate sections, and most surprisignly the mean organ device appeared to be all the way opposite these pipes over the entrance door, where another plethora of pipes were placed. This raised many questions: First, how does an organ work, Second, most of the pipes looked the same height, how do they play different notes, Third, the pipes seemed to run through solid rock columns and walls, how had they not been crushed and put out of tune by pressure, and Fourth, if one of the pipes did break, how could you possibly service or repair that if it exists within those hard and mastercrafted walls.

Answer 1

1. how does an organ work?
Simply Stated...
...the pipe organ is a big box of whistles. Each pipe sits on top of a hollow wind chest that is filled with compressed air provided by a bellows or blower. Each 'stop' at the organ console represents a set of pipes (a rank) of a particular tone color, with a different pipe for every note on the keyboard. Pulling the stop activates a slider under that specific set of pipes on the windchest, making them available as a sound-source. The wind chest also contains a series of valves (pallets) connected to the keyboard by a mechanical linkage. These pallets govern the flow of air to each pipe, and even though a stop may be 'on', no pipes will sound until a key is depressed and its respective pallet opens. This allows the compressed air to pass up through the pipe for that note, creating sound

2. Pipes appear to be the same height but may be sloped at the bottom. Also, they have many sets of pipes that produce different tones and imitate different instruments that play the same note but with a different sound, depending on their shape.

3. There are channels through the rock columns you cannot see. But they are there.

4. There are service areas inside the walls so they can get to every single pipe to clean or replace them.

Answer 2

The organ you describe is a Pipe Organ, and yes, they are WONDERFUL to look at -- as well as listen to. In a big room with lots of echoes, the do inspire people!!

The basic premise is that wind goes through those pipes, and like train whistles, etc causes them to vibrate. The organist presses keys that send the air into the pipes and you've got sound. Each pipe organ has an air box ("fan") as well as some very complex mechanicals that keep the whole thing going. They are very hard and expensive to maintain, including the fact that the must be kept in a climate-controlled area.

If you saw pipes of the same height, you saw a facade -- there are indeed dozens and dozens of pipes, from the size of a pencil to the size of a small missile!!

The pipes don't break unless something falls on them. The mechanicals that let the air thru break all the time, and no doubt there are passage ways (a la Starship Enterprise) to get to them.

Answer 3

The visible pipes you see are there just for show. The actual organ pipes are hidden behind the wall (usually near the front of a church) and emit their sound through openings to the sound box or chest, usually hidden by cloth like a loudspeaker grill. The working pipes are ugly tubes of various lengths and diameters connected to the wind chest or manifold by remotely operated valves. A motor-driven blower pressurizes the manifold slightly, but it’s main function is to deliver air in the volume required to “voice” each pipe.

If you ever get an opportunity to “go behind the scenes” to inspect the real organ you will be amazed at the ingenuity and complexity involved. There are also several devices hidden there to produce special sound effects, like bells or glockenspiels. Many old church organs are now in private hands, purchased to “save” them from the scrap heap. I tip my hat to those with the money to enjoy such a hobby. If you can find such a group near you, it is well worth the effort to try to get an “invite” to listen to a performance.