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
On The Nature of the Beast That Does Not Breathe
[A Few Words about Organ Actions]
[Some Basics of Notation]
[A Few Final Truths]
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[Newsletter Front Page]
Copyright © 2000 David Bohn. All rights reserved.
Last updated 12 November 2000. Contact information.