Klarinet Archive - Posting 000363.txt from 2002/11

From: LeliaLoban@-----.com
Subj: [kl] Affect of Hall Acoustics on Pitch: A question
Date: Thu, 7 Nov 2002 19:41:34 -0500

William Semple wrote,
>Where I'm coming from is that I have played a few
>church gigs, and staying in tune with an organ is a
>nifty accomplishment.

There's another reason for this problem besides the building's geometry.
Most pipe organ builders specify that the instrument will play in tune with
a=440 Hz at 70 degrees Fahrenheit. Change the temperature much (and, with
many pipe organs, change the humidity) and everything goes wicky-wacky.
Drives organists nuts, because of course some pipes (depending on their size,
composition and construction) change faster and more drastically than others,
while the building temperature changes depending on when (or whether) someone
remembered to turn on/off the heat/AC. More changes happen when the place
fills up with human bodies. The bottom line is that in most buildings, you
never have full use of the entire organ at any one time. That's *before* we
start talking about the general state of disrepair, the leaky wind chest, the
frayed leathers, the pipe way up in pigeon heaven that swallowed the dead
bat, etc..

When my uncle was resident organist at a large church, he used to leave notes
taped to the console to warn visiting organists of a whole litany of
potential nightmares. One was: Never pull certain stops in the late
afternoon when the sun had been shining through a certain stained glass
window for more than an hour, and wait until an hour after sundown to use
those ranks, because the sunbeams heated those particular pipes enough to
throw them out of pitch with the rest of the instrument. IMHO one of the
main reasons pipe organs feature so many harmonic corroborating stops is that
the complex overtones obscure the fact that the fundamental tones are all
over the place. Church choirs usually cope with pitch variations easily
enough, but bring in the instrumental players (especially the oboists) and
welcome to Acoustical Hell.

Lelia

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