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Setting A Scale

Guest Barry Oakley - voluntarily dereg

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Guest Barry Oakley

What is the precise method of setting an octave scale on a 4ft Principal. I know that initially several methods can be used such as tuning forks and a tuning meter, but strict use of such implements result in a too precise, uninteresting scale. I know that it is necessary to flatten fifths, but by how much? What are the actual notes involved in the scale of middle C to treble C?

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Guest Geoff McMahon

There are a number of ways of tuning and as is so often the case, no single one which can be called "right". Your comment about the slightly boring result when using a very accurately laid equal temperament (ET) is a valid and perceptive one. It is part of the reason of the interest in unequal temperaments has grown over the past twenty years and more. In any unequal temperament, each key has its own character.


One can of course use a meter for both ET and unequal temperaments. I prefer to do it by ear however. The main trouble with ET is that not only do all the keys have the same character, but also the thirds are way too sharp. If laying ET by ear, it is best to think of the intervals as "narrow" or "wide" rather than sharp or flat as the latter can be confusing. In ET, you need to make the fifths NARROW by about a beat and a half a second if working in the 2ft 8ve and the fourths about 2 beats a second WIDE. It is even better if you have any intervals higher up in the scale beating slightly faster than those lower down.


It is a little too complex to describe this in detail on a discussion board like this, but in general terms, if you make the fifths and fourths between F-C-G-D-A-E-B-F# all beat a little faster and the remainder a little slower, an acceptable compromise can be reached. This is similar to the Vallotti tuning which I will put below. That is a very good general use temperament and one I use often.


Here is a scheme for tuning Vallotti:


Set the A in the 2ft 8veof the 4ft Principal to the pitch you want

Tune E below to A at twice the speed of E.T. about 1.5 beats a second)

Tune B above to E also at twice the speed of E.T.

Then tune F# below to the B pure and on through C#(above)-G#(below)-D#(above)-A#(below)-F(also below) all pure fifths. Observe that any interval with a black note (be it the one you are tuning or the one you are tuning to) are pure in this tuning. This also applies when you are tuning up and down the tuning rank.

Next tune F-C(above)-G(below)-D(above)-A(below) all double the speed of E.T.

Then ensure that there is an even progression in all the tempered intervals with the fourths half as fast as the fifths and the intervals higher in the scale faster than the lower ones. If you have to move the A because the intervals F-C-G-D-A are beating too fast compared with the intervals A-E-B, you have tuned the first two intervals A-E-B too slow (and vice versa of course)

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  • 2 months later...

You could do worse than try to aquire a copy of "The well tempered Organ" by Charles Padgham published by John Brennan of the Positif Press Oxford. ISBN 0906894131. There used to be a cassette to go with the book to demonstrate the different temperaments described within. Anyone know if this interesting book is going to be reprinted and/or the audio re-issued on CD?

Oliver Horn.

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