Was/Sharp organ/Organ tuning

[Conrad Hoffsommer]

At 08:35 05/14/2001 -0400, you wrote:
>No solution....more related questions.
>
>Serious Pipe Organ questions/obsevations.....
>
>I question the tuning of the organ, It had been done the day before.
>Are Organs purposely offset due to the differential in the size of the
>pipes may cause different pipes to change with temperature at different
>rates?

Was the heat/air conditioning exactly the same as the day before??

Trying to tune a pipe organ is like trying to hit a moving target with a 
fixed artillery piece.

All the different metal pipe materials/alloys and wood have different 
coefficients of expansion. Changes in temperature affect metal pipes 
quickly - I've heard them change within seconds of turning the organ on 
where the blower was sucking in air at a different temperature than the 
room where the organ was located, or when someone left the swell shutters 
closed.

Changes in humidity quickly change the pitch of reed pipes - and usually in 
a different direction than any accompaning temperature change will move the 
flues.

Rising humidity tends to make pianos go sharp, but will make the wood ranks 
of an organ go flat.

>A440 Unisions between different sets of pipes do beat-- about 1 per
>second.

Celeste or "string" stops are purposely a little sharp _or_ flat to induce 
a "natural tremulant", otherwise there should be no beating.  Stops within 
a division (great/swell/choir/echo/posativ/pedal, etc.) shouldn't beat. 
Between divisions is where the moving target really comes in.

I don't _even_ wanna get into mutants and mixtures...

>Bass below F2 or so seem sharp to me.   Perhaps they use a machine.
>Any comments of organ idiosyncrasies appreciated.

Inharmonicity is generally so low as to be non-existant.


...and yes, organ tuners do tend to be a breed apart...



Conrad Hoffsommer - Music Technician -mailto:hoffsoco@luther.edu
Luther College, 700 College Drive, Decorah, Iowa 52101-1045
Voice-(563)-387-1204  //  Fax (563)-387-1076(Dept.office)

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