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The Development of the Equal Temperament Scale

Evolution or Radical Change?

Chapter 11
Abstract Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14

 

Data Analyzed in this Study

The main question this analysis seeks to answer is: Did the acceptance of the equal tempered scale fit into an evolutionary development or was it a radical departure from previously accepted methods?  The country of origin for each tuning is included in the analysis because of the influence this variable might have.  However, the study does not seek to answer any questions regarding the origin of each tuning method; the variable is only used to identify or account for any disparity in the data resulting from the variety of locations.

The tunings used for this research come from various sources, with the majority from Tuning and Temperament by J. Murray Barbour.[i]  Barbour used cents to analyze many historic temperaments.  He also included references to the initial publications of these methods.  Cross-referencing this data with tables found on the Internet, over ninety tunings with dates and countries of first publication are compiled for this research (Appendix A).  Equal temperament attempts were not included for this study.

There is no method to identify what tuning methods were prevalent for any given time or place.  Debate is still ongoing concerning which scale Bach’s Well Tempered Clavier was designed for.  If records are insufficient for a piece whose title alludes to a family of tuning systems, one can imagine the difficulty in accurately pinpointing the original temperament for other pieces.  In this study, tunings are ordered and placed by their dates and locations of first publication.  This is not an accurate portrayal of the music heard during those times, but theorists and mathematicians were probably influenced by the current practice and vice versa.  Rather than skewing the results by trying to assess which tunings were important (based on modern notions), no documented twelve note tuning system from Europe was purposely excluded from this data set.

The pitch systems were first analyzed by mean and standard deviation from three chosen standards: Equal Temperament, Just Intonation, and Pythagorean.  These were chosen because they are all somewhat static and are historically significant.  Total deviation values for a scale were calculated by adding the absolute value of differences between cent values of each note and the corresponding cent values from the standard.  This sum was then divided by eleven to obtain the mean deviation (see example below).  Eleven was used instead of thirteen because the first and last notes never change.

Example Calculation of Mean and Standard Deviation (using Silbermann w/ET as standard)

 

C

C#

D

D#

E

F

F#

G

G#

A

A#

B

C

Analyzed Scale (Silberman)

0

89

197

305

394

502

590

698

787

895

1003

1092

1200

Standard (equal temperament)

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

Absolute value of difference

0

11

3

5

6

2

10

2

13

5

3

8

0

 with corresponding cent values as .

0

121

9

25

36

4

100

4

169

25

9

64

0

Sum of Deviations

68

Mean of Deviations  

6.182

Standard Deviation

Standard deviations were calculated with the usual formula, replacing means with corresponding cents from the standard (see above).  Eleven was once again used for the number of samples.  Mean and standard deviations were listed and referred to in Barbour’s text, but he did not explain the calculations used to arrive at them.  Therefore, the deviation figures used for this research are not the same as those listed in Tuning and Temperament.

[i] Barbour, J. Murry.  Tuning and Temperament – A Historical Survey, (East Lansing: Michigan State College Press, 1951),

 

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Last modified: November 20, 2005