21L 1s

Revision as of 17:10, 11 December 2023 by Eliora (talk | contribs) (adopt mos intro)

21L 1s is a 2/1-equivalent (octave-equivalent) moment of symmetry scale containing 21 large steps and 1 small step, repeating every octave. 21L 1s is related to 1L 9s, expanding it by 12 tones. Generators that produce this scale range from 54.5 ¢ to 57.1 ¢, or from 1142.9 ¢ to 1145.5 ¢. Scales of this form are always proper because there is only one small step. Eliora proposes the name escapist for this pattern, referencing the escapade temperament which is supported by both 21edo and 22edo, thus covering the entire tuning spectrum.

← 20L 1s 21L 1s 22L 1s →
↙ 20L 2s ↓ 21L 2s 22L 2s ↘
Scale structure
Step pattern LLLLLLLLLLLLLLLLLLLLLs
sLLLLLLLLLLLLLLLLLLLLL
Equave 2/1 (1200.0 ¢)
Period 2/1 (1200.0 ¢)
Generator size
Bright 1\22 to 1\21 (54.5 ¢ to 57.1 ¢)
Dark 20\21 to 21\22 (1142.9 ¢ to 1145.5 ¢)
TAMNAMS information
Related to 1L 9s (antisinatonic)
With tunings 12:1 to 13:1
Related MOS scales
Parent 1L 20s
Sister 1L 21s
Daughters 22L 21s, 21L 22s
Neutralized 20L 2s
2-Flought 43L 1s, 21L 23s
Equal tunings
Equalized (L:s = 1:1) 1\22 (54.5 ¢)
Supersoft (L:s = 4:3) 4\87 (55.2 ¢)
Soft (L:s = 3:2) 3\65 (55.4 ¢)
Semisoft (L:s = 5:3) 5\108 (55.6 ¢)
Basic (L:s = 2:1) 2\43 (55.8 ¢)
Semihard (L:s = 5:2) 5\107 (56.1 ¢)
Hard (L:s = 3:1) 3\64 (56.2 ¢)
Superhard (L:s = 4:1) 4\85 (56.5 ¢)
Collapsed (L:s = 1:0) 1\21 (57.1 ¢)
ViewTalkEdit

Moremajorthanmajor proposes the name tricesimoprimal quartertonic for this pattern since its harmonic entropy minimum corresponds to tempering out the unnamed comma 961/960 - the tricesimoprimal quartertones being equated with each other. In addition, both 21edo and 22edo, extreme ranges of the MOS do not temper out this comma, while EDOs up to 100-200 which have this scale do.

Tuning ranges

The scale's approach to standard harmony can be considered based on the mode.

Brighter modes

Diatonic fifth and 65edo (Ultrasoft and supersoft)

Between 3\65 and 1\22, 13 steps amount to a diatonic fifth, which corresponds to the ultrasoft step ratio range. In 65edo, the fifth produced by 13 steps of the tricesimoprimal quartertonic scale is the same as 3 steps of 5edo, and thus is the exact boundary between a fifth proper and a fifth-sixth.

If the pure 32/31 is used as a generator, the resulting fifth is 714.53756 cents, which puts it in the category around Ultrapyth.

Fifth-sixth (hard of supersoft)

From 1\21 to 3\65, 13 steps amount to a fifth-sixth.

If the pure 31/30 is used as a generator, the resulting fifth-sixth is 737.96915 cents, which puts it in the category around father/petritri/aurora.

Darker modes

If instead the small step is stacked down, this enables the scale to approximate the standard 4:5:6 and 10:12:15 triads, as the escapade temperament does.

The escapade temperament reaches 4/3 in 9 gensteps, meaning that modes from Hermit (12|9) onward support a perfect fifth from the tonic. This also enables the modes from Hermit through Temperance (7|14) to support the major triad, 4:5:6, and from Devil (6|15) onward to support the minor triad, 10:12:15. The 700 cent fifth is supported in 108edo, stacking steps of 5\108 downward.

Relation to other equal divisions

2 steps act as a pseudo-16/15, and when they actually act as 16/15, 961/960 is tempered out.

Modes

The author proposes naming the modes after Tarot Major Arcana adjectivals based on how many generators down there is since there are 22 of them.

Mode Name
21|0 Foolish
20|1 Magical
19|2 High Priestess's
18|3 Empress's
... ...
3|19 Lunar
2|19 Solar
1|20 Judgemental
0|21 Worldwide

Scale tree

Generator L s L/s Comments
1\22 1 1 1.000
6\131 6 5 1.200
5\109 5 4 1.250
9\196 9 7 1.286
4\87 4 3 1.333
11\239 11 8 1.375
7\152 7 5 1.400
10\217 10 7 1.428
3\65 3 2 1.500 13 steps adding to upper bound of diatonic fifths (720¢) is here
11\238 11 7 1.571
8\173 8 5 1.600
13\281 13 8 1.625
5\108 5 3 1.667 Inverting the scale yields a 700 cent fifth
12\259 12 7 1.714
7\151 7 4 1.750
9\194 9 5 1.800
2\43 2 1 2.000 Basic escapist
9\193 9 4 2.250
7\150 7 3 2.333
12\257 12 5 2.400
5\107 5 2 2.500
13\278 13 5 2.600
8\171 8 3 2.667
11\235 11 4 2.750
3\64 3 1 3.000
10\213 10 3 3.333
7\149 7 2 3.500
11\234 11 3 3.667
4\85 4 1 4.000
9\191 9 2 4.500
5\106 5 1 5.000
6\127 6 1 6.000
1\21 1 0 → inf

See also