My quest for a "Standard Hole Spacing" for the hurdy-gurdy music roll
is becoming complicated.  Ingmar Krause reports that the Carl Frei
scale became the standard scale for the paper-roll-controlled German
Drehorgel.  But there are compatibility problems.

Two main questions arise:

   1. What standard did Carl Frei declare and use?

   2. What standard should be used _today_ for best compatibility
      when punching music rolls?

The Jaeger & Brommer roll which I measured is 110 mm wide, and the
spacing is 3.89 mm/hole.

On page 285 in the book, "Waldkircher Dreh- und Jahrmarkt Orgeln" by
Herbert Jutteman, is the key-scale used in Carl Frei organs of 20 to 22
keys.  The annotation says that the small Carl Frei organs measured by
Jutteman used a paper roll of width 110 mm, and the hole spacing was
3.86 mm.  (On adjacent pages are the scales and measure- ments of many
other organs, including models by Ruth and Alfred Bruder which used
3.85 mm spacing.)

This dimension matches nicely the measurement system formerly used in
Bruchsal and probably other cities in Baden.  The "Bruchsal Foot" was
279.65 mm long (expressed in the modern Metric system) and was divided
into 12 inches; the inch was further subdivided into twelve parts, each
therefore 269.65/144 = 1.942 mm.  If Carl Frei or his predecessors used
2 small divisions for each hole, the spacing would be 3.884 mm per
hole.  That's pretty good agreement!  But my theory is only conjecture.
...

Compatibilty, today, is a big problem.  Subscriber Hal O'Rourke has a
template which he uses to check the hole spacing of music rolls from
different vendors.  He wrote to me:

> The reason I have the template is that "production" tracker bars
> vary from builder to builder.  On a recent trip to Europe for a
> festival, Melvyn Wright gave me the template to try on lots of
> different organs and we CONFIRMED this.  He had been getting
> complaints that his music rolls didn't work for certain customers.
> Some varied by as much as _half a hole_ by the time you got to the
> 20th note.
>
> Some builders make their own tracker bars from wood and they vary
> most, but I even found brass bars that were way out. If you're
> going to try to publish a standard you may want to measure a
> Raffin because there are more of his organs out there, and I would
> trust him more than some. I would hate to see bad information out
> there.

Subscriber Philip Jamison agrees:

> I'm writing an article for the MBSI Journal about new organs, and
> any information you come up with on the various scales would be
> helpful.  I read Hal O'Rourke's comments on the 20-note roll scale,
> and it [the problem] seems almost universal.  I can't tell whose
> rolls interchange with whose from the factory literature.

I'd like to get more information on this matter from the organ-
builders themselves.  Perhaps a modern Standard will develop, and
templates like Melvyn Wright's will no longer be needed.  That's why
standards exist, and that's why the American music roll industry
blossomed.

-- Robbie Rhodes

• ----------------------------------
|         Robbie Rhodes            |
| Return-Path: rrhodes@foxtail.com |
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