365edo/Eliora's approach

Revision as of 13:55, 17 September 2023 by Eliora (talk | contribs)

Theory

As 365 is the number of days in the common year, and there is a way to implement such a fact into music. An octave stretch of -0.796 cents would compress 365edo to an interesting intepretation: the pure 2/1 would represent 365.24219edo, which is the length of solar days in a tropical year. In 23-limit, 365eeffgghiii val's octave stretch of -0.79428 cents is very close, and makes 2/1 correspond to 365.241917 days, or 365 days 5h 48m 21.7s, which is only about 20 seconds short of the tropical year in the present era.

This approach will cover what is essentially "tropical year"-EDO, that is 365.2422edo using the 365eeffgghiii val. Therefore, each step is equal to 3.2854936 cents, and there are common octaves consisting of 365 steps and leap octaves consisting of 366 steps.

In the 7-limit, the val is the same as patent val for 365edo, and hence it supports the hemiwürschmidt temperament just like the unstretched pure-octave 365edo does.

Mapping used

2 3 5 7 11 13 17 19 23
Map 365 579 848 1025 1264 1352 1493 1551 1653
Reduced 365 214 118 295 169 257 33 91 193


Table of intervals

Step Note name Interval name Associated Ratio

based on 365eeffgghiii

0 January 1 Prime, unison 1/1
32 February 1 Dodecaphonic semitone
33 February 2 Septendecimal semitone 17/16
59 February 28
59 II February 29 inserted once every 4 octaves accumulating octave stretch
60 March 1 Dodecaphonic major second
63 March 4 Classical major second, meantone 9/8
91 April 1 Undevicesimal minor third, dodecaphonic minor third 19/16
118 April 28 Classical major third 5/4
169 June 18 Undecimal superfourth 11/8
182 July 1 Dodecaphonic tritone
193 July 12 Vicesimotertial lalala 23/16
214 August 2 Perfect fifth 3/2
257 September 14 Tridecimal neutral sixth 13/8
295 October 22 Harmonic seventh 7/4
365 January 1 Octave 2/1

Rank two temperaments by generator

Generator

(reduced)

Temperament Calendar name
181\365 121i & 365eeffgghiii June 30
59\365 99ef & 365eeffgghiii February 28
172\365 87 & 365eeffgghiii June 21
107\365 58hi & 365eeffgghiii April 17