Weird Temperament

Bradley M. Snook bsnook@pacbell.net
Sat, 13 Apr 2002 03:05:57 -0700


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Yes, I would agree with you about the oddity of this temperament, but I am pretty sure that I know what happened. To me it sounds like this is a kind of Kirnberger II temperament, with some modifications and some misunderstandings all mixed together:

 

The temperament should have started on C instead of A. Unfortunately, the only way to make the directions you were given make sense is to use A as a starting note for the temperament. This is not such a huge deal, but it may have caused some confusion in the transposition.

 

With a temperament based on a cycle of fifths, there should be alterations that total a -23.46 cent comma. Now in theory, this amount can be distributed, either equally or unequally, among any number of intervals (1-12). Kirnberger II has two unequal tempered intervals. The following is Kirnberger II transposed with A as the starting note:

 

A         440.00

D         586.66 [P5 down]

G         782.22 [P5 down]

C         521.48 [P5 down]

F          695.31 [P5 down]

Bflt       463.54 [P5 down]

 

(A        440.00)

E          660.00 [P5 up]

B          495.00 [P5 up]

 

(A        440.00)

C#       550.00  [M3 up]

G#       825.00  [P5 up]

D#       618.75  [P5 up]

 

F# is tempered with an equal beat rate between D-F# [M3] and F#-B [P4]

 

D-F# as a Just M3 would make F# 733.32

F#-B as a Just P4 would make F#  742.50

To get an equal beat rate add the two frequencies and divide by two:

 

F#        737.91  [Equal Beating]

 

 

 

The "Other" temperament

Tune by Just 5ths

E should be tempered A and B [mean tone?]

F# should be a Just M3 with D

 

(First tune the cycle without the tempered E)

A         440

E          660

B          495

F#        742.5

C#       556.87

G#       835.32

D#       626.48

A#       469.86

F          352.40

C         528.60

G         792.89

 

Next tune D as a Just M3 to F#:

 

D         594

 

I am not sure I understand exactly how to make E a meantone between A and B. Generally a meantone temperament uses narrow 4ths and wide 5ths. The only thing that I can think of is that that you tune A - E - B, and then lower E to make a widened 5th between E-B (a widened 5th between A-E would be reverse temperament, so that will not work). But how much should it be lowered? How do you tell? The only way to make this work [with only two tempered intervals] is to let E absorb the rest of the comma (-21.576): 

 

E          651.83       (-8 bps)

 

 







After you follow through with the rest of the adjustments, the frequencies should be as listed below (hopefully I haven't made too many calculation errors):

 

Kirnberger II             "The Other"

A      440                     440

A#    469.9                  469.9

B       495                     495

C      528.6                  528.6

C#    556.9                  556.9

D      594.67                594

D#    618.7                  626.5

E      660                     651.83

F       704.8                  704.8

F#    737.9                  742.5

G      792.9                  792.9

G#    825                     835.32

 

 

 

I told him that there weren't going to be any thirds tuned "pure" in the Kirnberger.

Well, Kirnberger II does have one M3, which normally falls on C-E. The M3 is used to lower the amount of the comma by -21.5 cents. Remember the total comma is only -23.462 cents.

 

And if any of the historical temperaments would have a pure third, it would be C-E. Was I wrong?

Not at all . . . well a little bit. The general understanding is that well temperaments will start on C and then move away. The result is that the closer you remain in relation to C, the more harmonious the key area will sound. But there is nothing stopping a tuner from starting on C# instead!

 

 

 

One last interesting note: in working through the calculations of Kirnberger II, I found that the comma never really gets properly absorbed. The M3 accounts for -21.5 cents, but the interval tempered with equal beating rates between M3 and P4 add an additional -10.7 cents; this means that this last interval was tempered too much (+8.7 cents). To officially close the loop, set the intervals to beat equally, and then raise the tempered interval slightly.

 

 

Bradley M. Snook


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