Re: The Tracker Organ
By Craig Brougher
I forgot to say, in my letter about terms, why I thought that the wooden rods which open the note pallets are called "trackers."
I believe the builders of these organs called the pull-down linkages "trackers" because they track the motion of the key in the same plane. When building one of these organs, the "tracker" is about the last linkage to be added. Up until then, you have sometimes, linkages going all over the place. Then when you hang the trackers, it ties the fan frame all together and you see them suddenly connecting the key motion to the pallet wires. So I'm sure the name "tracker" just came to mind to describe what they expected to see when they tied in the back-fall action to the pallets.
A trackerbar therefore is a logical name for something similar which ties in the firmware we call a player roll with the pneumatic action. It "tracks" the roll placed on it. Tracker, I suggest, just referred to a mechanical interface between the intentioned source of the music and the machine.
Tracker bars and tracker organs haven't the faintest connection with each other, except with the name, "tracker- whatever." There is a wind chest called a tracker chest, and is a carryover from the original tracker organ. The smallest form of tracker chest can be seen in the little reed organs. As you can see, the pallets are operated directly by the "push-pin" ( which is filed to level each key individually).
The backbone of the wind chest in an American tracker organ of the early 20th century was called a "wind-bar." Hmmm. Combine wind-bar with tracker action, and you have "tracker-bar." (Windbars bolstered the chest and helped prevent sagging in the heavy pedal stops). But that isn't what I wanted to say.
The "Tracker Wind Chests" are operated by pallets in their bottoms, in which is screwed a hook eye. From the hook is a wire called a pull-down which exits the bottom of the chest through a bushing.
In some pneumatically controlled organs, these pull-down wires are operated directly by pneumatics, or in some versions, like some Mortiers, external pouches in strips under the wind chests are used. These are still called tracker wind chests because they came directly from tracker organ design, NOT because they are now operated by trackerbars, etc.
There is absolutely no such thing as a "Tracker Organ" being operated by an electrical abstract or pneumatic valve system. However, there are tracker organs to which these abstract systems have been added! If we will faithfully preserve the original terminology and adamantly refuse to get confused or cavalier with our terms, we will be much better served, I believe. Most tracker organs today, as built in the twentieth century, probably do have electrical interfaces. That is not the tracker part of the organ, as you will see shortly.
Below are some terms as I have understood them. I'm sure that others probably have different names for these same things, and depending on my mood, I would probably give them different names too, on occasion.
In a manual tracker action organ, however, above the key is the felted (and sometimes weighted) "thumping board;" just like in a piano, it prevents the keys from hopping too high (overshoot) when the finger slides off abruptly. In front of the key is a "Front Rail" to adjust the key travel, just like in a piano, also. Then at the back of the key there is a stick, called a "sticker." It will be vertical if it is to be called a sticker. "Back-falls" are horizontal boards like keys, used to "fan" the sticker positions out for better access and alignment. The "Back-Fall" in turn is connected to vertical, thin, light sticks called "Trackers." This is where the organ takes its name.
The overall lever system used to get to the pallet valve (and sliders) in the wind chest arrangement is called "The Fan-Frame." The design ideal is to keep the main (moveable) elements more or less vertical, as much as possible; otherwise, in a large organ, you will have too much bending (moments) and the lost motion will vary, depending on the weather, dust and dirt in the action elements and too many "Centers" per note. That is why a good tracker organ requires a very tall loft, and the multiple chests are more or less stacked in two or three columns above it.
Other linkage elements are also used to couple the keys and stops to pallets and sliders. Some of their names might be, "Squares, Roller Arms, Roller Brackets, Tracker Connectors, Tracker Tops, Hangers, etc."
Just thought you would like to know however, where the tracker organ gets its name, and it _definitely_ has nothing to do with a "trackerbar."
Craig Brougher
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(Message sent Sun 19 Jan 1997, 15:04:31 GMT, from time zone GMT.) |
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