What is an organ demonstration?
Pipe organs are marvelous machines as well as musical instruments with a long history. In this demonstration you will learn how the instrument works, hear selections of individual stops (voices), combinations of stops, and music to illustrate the range of colors available.
There are two kinds of pipe organs: mechanical action and electro-pneumatic action. In a mechanical action organ there is a direct mechanical link from each key on the keyboard to each pallet (the valve that lets air into the pipes). In electro-pneumatic organs, the pallets are operated by electro-magnets that are controlled by the keys on the keyboard via electric wires.
We much prefer to demonstrate mechanical action instruments. Depending on the location, you will be able to see the organs up close and examine some of their inner workings.
What about the music?
You will hear music that has been carefully selected to illustrate the range of sounds that can be produced by these instruments. The works will be performed by professional organists.
Cross section of wind-chest showing pallet (H) and pull-down wire (N).
"A direct mechanical link between the performer and the valve [pallet] that allows wind to the pipes gives the performer the ability to control the attack and release of the pipes. This can bring very subtle and expressive capabilities to the music that cannot be achieved with an electric or electro-pneumatic action, which always lets the air to the pipes in the same way, no matter how the key is depressed or released. Also the mechanical system is much simpler, straightforward and longer lived with fewer maintenance hassles."
---Steve Dieck, C.B. Fisk Company
To learn more about organ demonstrations, visit http://www.organdemo.info/