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 On the Nature of the Beast That Does Not Breathe
>A Few Words about Organ Actions
Some Basics of Notation
Extended Techniques
A Few Final Truths

A Few Words about "Organ Actions"

The "action" of the organ refers the way the organist controls the opening and closing of various valves within the organ, and there are many terms used to describe the nature of organ actions. The action itself consists of two parts: the stop action, which controls the registration (what stops are on), and the key action, which controls which pitches sound. These actions are independent of each other; for example, an organ may have a mechanical key action and an electric or stop action, which is a popular arrangement nowadays.

Composers should acquaint themselves with the following terms:

Mechanical (or Tracker)
The keys or stopknobs are mechanically connected to the valves they control. This type of action is the oldest, and many organists consider it best in that it gives them the illusion of precise control over what is occurring. The prime weakness of a mechanical action is that it gets harder to control (particularly the stop action or the key action when couplers are engaged) on a larger instrument.

Electric (or Electro-Pneumatic, or Electro-Mechanical)
The keys or stopknobs operate contacts that cause the desired valves to open or close as desired; electric actions are strictly on or off, with nothing halfway. While the organist loses all of the sense of precise control they have with mechanical action (particularly when electricity is applied to the key action), there are a few things that an electrically controlled action will allow that a mechanical action will not allow.

Tubular-Pneumatic (or simply Pneumatic)
A transitional action that was used in the 19th and early 20th centuries and that is used only occasionally in limited ways in contemporary organ building. Operating on pressurized air, a pneumatic type action alleviated some of the problems mechanical actions had in controlling a large organ, but it ultimately proved problematic (particularly where large distances were involved) and was abandoned in favor of the electrical types of action.

Found occasionally nowadays and most typically applied to only the stop action, "tandem" implies that there are actually two separate actions in operation. While this is arguably superior to the use of any single action, it is the most expensive option, and it frequently precludes options that are readily available on a purely electrical action.

On The Nature of the Beast That Does Not Breathe
[Introduction] [A Few Words about Organ Actions] [Some Basics of Notation]
[Registrations] [Extended Techniques] [A Few Final Truths] [Appendixes]

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Copyright © 2000 David Bohn. All rights reserved.
Last updated 12 November 2000. Contact information.