7L 3s: Difference between revisions
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{{Infobox MOS | {{Infobox MOS | ||
| Name = dicotonic | | Name = dicotonic | ||
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}} | }} | ||
'''7L 3s | '''7L 3s''' refers to the structure of [[MOSScales|moment of symmetry scales]] built from a 10-tone chain of neutral thirds (assuming a period of an octave): | ||
L s L L L s L L s L | L s L L L s L L s L | ||
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t q t t t q t t q t | t q t t t q t t q t | ||
==Names== | == Names== | ||
This MOS is called '''dicotonic''' (named after the abstract temperaments [[dicot]] and more specifically 11-limit [[Dicot_family#Dichotic|dichotic]]) in [[TAMNAMS]]. | This MOS is called '''dicotonic''' (named after the abstract temperaments [[dicot]] and more specifically 11-limit [[Dicot_family#Dichotic|dichotic]]) in [[TAMNAMS]]. | ||
==Intervals== | ==Intervals== | ||
The generator (g) will fall between 343 cents (2\7 - two degrees of [[7edo]] and 360 cents (3\10 - three degrees of [[10edo]]), hence a neutral third. | The generator (g) will fall between 343 cents (2\7 - two degrees of [[7edo|7edo]] and 360 cents (3\10 - three degrees of [[10edo|10edo]]), hence a neutral third. | ||
2g, then, will fall between 686 cents (4\7) and 720 cents (3\5), the range of [[5L 2s|diatonic]] fifths. | 2g, then, will fall between 686 cents (4\7) and 720 cents (3\5), the range of [[5L 2s|diatonic]] fifths. | ||
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!# generators up | !# generators up | ||
!Notation (1/1 = 0) | !Notation (1/1 = 0) | ||
!name | ! name | ||
!In L's and s's | !In L's and s's | ||
!# generators up | !# generators up | ||
!Notation of 2/1 inverse | ! Notation of 2/1 inverse | ||
!name | ! name | ||
!In L's and s's | ! In L's and s's | ||
|- | |- | ||
| colspan="8" style="text-align:center" |The 10-note MOS has the following intervals (from some root): | | colspan="8" style="text-align:center" |The 10-note MOS has the following intervals (from some root): | ||
|- | |- | ||
|0 | | 0 | ||
|0 | |0 | ||
|perfect unison | |perfect unison | ||
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|7L+3s | |7L+3s | ||
|- | |- | ||
|1 | | 1 | ||
|7 | | 7 | ||
|perfect 7-step | |perfect 7-step | ||
|5L+2s | |5L+2s | ||
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|1 | |1 | ||
|major (1-)step | |major (1-)step | ||
|1L | | 1L | ||
| -3 | | -3 | ||
|9v | |9v | ||
|minor 9-step | | minor 9-step | ||
|6L+3s | |6L+3s | ||
|- | |- | ||
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|8 | |8 | ||
|major 8-step | |major 8-step | ||
|6L+2s | | 6L+2s | ||
| -4 | | -4 | ||
|2v | |2v | ||
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|major 5-step | |major 5-step | ||
|4L+1s | |4L+1s | ||
| -5 | | -5 | ||
|5v | |5v | ||
|minor 5-step | | minor 5-step | ||
|3L+2s | | 3L+2s | ||
|- | |- | ||
|6 | |6 | ||
|2 | |2 | ||
|major 2-step | | major 2-step | ||
|2L | |2L | ||
| -6 | | -6 | ||
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|9 | |9 | ||
|major 9-step | |major 9-step | ||
|7L+2s | | 7L+2s | ||
| -7 | | -7 | ||
|1v | |1v | ||
|minor (1-)step | | minor (1-)step | ||
|1s | |1s | ||
|- | |- | ||
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|6^ | |6^ | ||
|major 6-step | |major 6-step | ||
|5L+1s | | 5L+1s | ||
| -8 | | -8 | ||
|4v | |4v | ||
|minor 4-step | |minor 4-step | ||
|2L+2s | | 2L+2s | ||
|- | |- | ||
|9 | |9 | ||
|3^ | |3^ | ||
|augmented 3-step | | augmented 3-step | ||
|3L | |3L | ||
| -9 | | -9 | ||
|7v | |7v | ||
|diminished 7-step | |diminished 7-step | ||
| 4L+3s | |4L+3s | ||
|- | |- | ||
|10 | |10 | ||
|0^ | |0^ | ||
|augmented unison | | augmented unison | ||
|1L-1s | |1L-1s | ||
| -10 | | -10 | ||
Line 153: | Line 144: | ||
|11 | |11 | ||
|7^ | |7^ | ||
|augmented 7-step | | augmented 7-step | ||
|6L+1s | |6L+1s | ||
| -11 | | -11 | ||
|3v | |3v | ||
|diminished 3-step | |diminished 3-step | ||
| 1L+2s | |1L+2s | ||
|- | |- | ||
| colspan="8" style="text-align:center" |The chromatic 17-note MOS (either [[7L 10s]], [[10L 7s]], or [[17edo]]) also has the following intervals (from some root): | | colspan="8" style="text-align:center" |The chromatic 17-note MOS (either [[7L 10s]], [[10L 7s]], or [[17edo]]) also has the following intervals (from some root): | ||
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|12 | |12 | ||
|4^ | |4^ | ||
|augmented 4-step | | augmented 4-step | ||
|4L | |4L | ||
| -12 | | -12 | ||
|6v | | 6v | ||
|diminished 6-step | |diminished 6-step | ||
|3L+3s | |3L+3s | ||
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|2L-1s | |2L-1s | ||
| -13 | | -13 | ||
|9w | | 9w | ||
|diminished 9-step | |diminished 9-step | ||
|5L+4s | |5L+4s | ||
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|augmented 8-step | |augmented 8-step | ||
|8L+1s | |8L+1s | ||
| -14 | | -14 | ||
|2w | |2w | ||
|diminished 2-step | |diminished 2-step | ||
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|15 | |15 | ||
|5^ | |5^ | ||
| augmented 5-step | |augmented 5-step | ||
|5L | | 5L | ||
| -15 | | -15 | ||
|5w | |5w | ||
|diminished 5-step | | diminished 5-step | ||
|2L+3s | |2L+3s | ||
|- | |- | ||
|16 | |16 | ||
|2^ | |2^ | ||
|augmented 2-step | | augmented 2-step | ||
| 3L-1s | |3L-1s | ||
| -16 | | -16 | ||
|8w | |8w | ||
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|4L+4s | |4L+4s | ||
|} | |} | ||
==Scale tree == | == Scale tree == | ||
The generator range reflects two extremes: one where L = s (3\10), and another where s = 0 (2\7). Between these extremes, there is an infinite continuum of possible generator sizes. By taking freshman sums of the two edges (adding the numerators, then adding the denominators), we can fill in this continuum with compatible edos, increasing in number of tones as we continue filling in the in-betweens. Thus, the smallest in-between edo would be (3+2)\(10+7) = 5\17 – five degrees of [[17edo]]: | The generator range reflects two extremes: one where L = s (3\10), and another where s = 0 (2\7). Between these extremes, there is an infinite continuum of possible generator sizes. By taking freshman sums of the two edges (adding the numerators, then adding the denominators), we can fill in this continuum with compatible edos, increasing in number of tones as we continue filling in the in-betweens. Thus, the smallest in-between edo would be (3+2)\(10+7) = 5\17 – five degrees of [[17edo]]: | ||
{| class="wikitable center-all" | {| class="wikitable center-all" | ||
! colspan=" | ! colspan="6" rowspan="2" | Generator | ||
! colspan="2" | Cents | ! colspan="2" | Cents | ||
! rowspan="2" | L | |||
! rowspan="2" |L | ! rowspan="2" | s | ||
! rowspan="2" |s | ! rowspan="2" | L/s | ||
! rowspan="2" |L/s | ! rowspan="2" | Comments | ||
! rowspan="2" |Comments | |||
|- | |- | ||
! | ! Chroma-positive | ||
! | ! Chroma-negative | ||
|- | |- | ||
|7\10|| || || ||840.000|| | | 7\10 || || || || || || 840.000 || 360.000 || 1 || 1 || 1.000 || | ||
|- | |- | ||
| | | || || || || || 40\57 || 842.105 || 357.895 || 6 || 5 || 1.200 || Restles↑ | ||
|- | |- | ||
| | | || || || || 33\47 || || 842.553 || 357.447 || 5 || 4 || 1.250 || | ||
| | |||
| | |||
| | |||
|842. | |||
| | |||
| | |||
| | |||
| | |||
|1. | |||
| | |||
|- | |- | ||
| | | || || || || || 59\84 || 842.857 || 357.143 || 9 || 7 || 1.286 || | ||
| | |||
| | |||
| | |||
|842. | |||
| | |||
| | |||
| | |||
| | |||
|1. | |||
| | |||
|- | |- | ||
| | | || || || 26\37 || || || 843.243 || 356.757 || 4 || 3 || 1.333 || | ||
| | |||
|- | |- | ||
| | | || || || || || 71\101 || 843.564 || 356.436 || 11 || 8 || 1.375 || | ||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
|11 | |||
|1. | |||
| | |||
|- | |- | ||
| | | || || || || 45\64 || || 843.750 || 356.250 || 7 || 5 || 1.400 || Beatles | ||
| | |||
|- | |- | ||
| | | || || || || || 64\91 || 843.956 || 356.044 || 10 || 7 || 1.428 || | ||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
|10 | |||
|1. | |||
| | |||
|- | |- | ||
| | | || || 19\27 || || || || 844.444 || 355.556 || 3 || 2 || 1.500 || L/s = 3/2, suhajira/ringo | ||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
|1. | |||
| | |||
|- | |- | ||
| | | || || || || || 69\98 || 844.698 || 355.102 || 11 || 7 || 1.571 || | ||
| | |||
|- | |- | ||
| | | || || || || 50\71 || || 845.070 || 354.930 || 8 || 5 || 1.600 || | ||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
|1. | |||
| | |||
|- | |- | ||
| | | || || || || || 81\115 || 845.217 || 354.783 || 13 || 8 || 1.625 || Golden suhajira | ||
| | |||
|- | |- | ||
| | | || || || 31\44 || || || 845.455 || 354.545 || 5 || 3 || 1.667 || | ||
| | |||
|- | |- | ||
| | | || || || || || 74\105 || 845.714 || 354.286 || 12 || 7 || 1.714 || | ||
|- | |- | ||
| | | || || || || 43\61 || || 845.902 || 354.098 || 7 || 4 || 1.750 || | ||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
|1. | |||
| | |||
|- | |- | ||
| | | || || || || || 55\78 || 846.154 || 353.846 || 9 || 5 || 1.800 || | ||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
| | |||
| ||55\78 | |||
| | |||
|- | |- | ||
|12\17|| || | | || 12\17 || || || || || 847.059 || 352.941 || 2 || 1 || 2.000 || Basic dicotonic<br>(Generators smaller than this are proper) | ||
|- | |- | ||
| | | || || || || || 53\75 || 848.000 || 352.000 || 9 || 4 || 2.250 || | ||
|- | |- | ||
| ||41\58 | | || || || || 41\58 || || 848.273 || 351.724 || 7 || 3 || 2.333 || | ||
|- | |- | ||
| || ||70\99 | | || || || || || 70\99 || 848.485 || 351.515 || 12 || 5 || 2.400 || Hemif/hemififths | ||
|- | |- | ||
|29\41 | | || || || 29\41 || || || 848.780 || 351.220 || 5 || 2 || 2.500 || Mohaha/neutrominant | ||
|- | |- | ||
| || ||75\106 | | || || || || || 75\106 || 849.057 || 350.943 || 13 || 5 || 2.600 || Hemif/salsa/karadeniz | ||
|- | |- | ||
| ||46\65|| | | || || || || 46\65 || || 849.231 || 350.769 || 8 || 3 || 2.667 || Mohaha/mohamaq | ||
|- | |- | ||
| || ||63\89 | | || || || || || 63\89 || 849.438 || 350.562 || 11 || 4 || 2.750 || | ||
|- | |- | ||
|17\24|| || || ||850.000||350.000 | | || || 17\24 || || || || 850.000 || 350.000 || 3 || 1 || 3.000 || L/s = 3/1 | ||
|- | |- | ||
| || ||56\79 | | || || || || || 56\79 || 850.633 || 349.367 || 10 || 3 || 3.333 || | ||
|- | |- | ||
| ||39\55 | | || || || || 39\55 || || 850.909 || 349.091 || 7 || 2 || 3.500 || | ||
|- | |- | ||
| || ||61\86 | | || || || || || 61\86 || 851.613 || 358.837 || 11 || 3 || 3.667 || | ||
|- | |- | ||
|22\31|| | | || || || 22\31 || || || 851.613 || 348.387 || 4 || 1 || 4.000 || Mohaha/migration/mohajira | ||
|- | |- | ||
| || ||49\69 | | || || || || || 49\69 || 852.174 || 347.826 || 9 || 2 || 4.500 || | ||
|- | |- | ||
| ||27\38|| | | || || || || 27\38 || || 852.632|| 347.368 || 5 || 1 || 5.000 || | ||
|- | |- | ||
| || | | || || || || || 32\45 || 853.333 || 346.667 || 6 || 1 || 6.000 || Mohaha/ptolemy | ||
|- | |- | ||
|5\7|| || || ||857.143|| 342.867 | | 5\7 || || || || || || 857.143 || 342.867 || 1 || 0 || → inf || | ||
|} | |} | ||
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You can also build this scale by stacking neutral thirds that are not members of edos – for instance, frequency ratios 11:9, 49:40, 27:22, 16:13 – or the square root of 3:2 (a bisected just perfect fifth). | You can also build this scale by stacking neutral thirds that are not members of edos – for instance, frequency ratios 11:9, 49:40, 27:22, 16:13 – or the square root of 3:2 (a bisected just perfect fifth). | ||
==Rank-2 temperaments== | == Rank-2 temperaments == | ||
==7-note subsets == | ==7-note subsets== | ||
If you stop the chain at 7 tones, you have a heptatonic scale of the form [[3L 4s]]: | If you stop the chain at 7 tones, you have a heptatonic scale of the form [[3L_4s|3L 4s]]: | ||
L s s L s L s | L s s L s L s | ||
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which is not a complete moment of symmetry scale in itself, but a subset of one. | which is not a complete moment of symmetry scale in itself, but a subset of one. | ||
== Tetrachordal structure== | ==Tetrachordal structure== | ||
Due to the frequency of perfect fourths and fifths in this scale, it can also be analyzed as a [[tetrachord|tetrachordal scale]]. The perfect fourth can be traversed by 3 t's and a q, or 2 t's and a T. | Due to the frequency of perfect fourths and fifths in this scale, it can also be analyzed as a [[tetrachord|tetrachordal scale]]. The perfect fourth can be traversed by 3 t's and a q, or 2 t's and a T. | ||
Revision as of 09:04, 2 April 2022
↖ 6L 2s | ↑ 7L 2s | 8L 2s ↗ |
← 6L 3s | 7L 3s | 8L 3s → |
↙ 6L 4s | ↓ 7L 4s | 8L 4s ↘ |
┌╥╥╥┬╥╥┬╥╥┬┐ │║║║│║║│║║││ ││││││││││││ └┴┴┴┴┴┴┴┴┴┴┘
sLLsLLsLLL
7L 3s refers to the structure of moment of symmetry scales built from a 10-tone chain of neutral thirds (assuming a period of an octave):
L s L L L s L L s L
Graham Breed has a page on his website dedicated to 7+3 scales. He proposes calling the large step "t" for "tone", lowercase because the large step is a narrow neutral tone, and the small step "q" for "quartertone", because the small step is often close to a quartertone. (Note that the small step is not a quartertone in every instance of 7+3, so do not take that "q" literally.) Thus we have:
t q t t t q t t q t
Names
This MOS is called dicotonic (named after the abstract temperaments dicot and more specifically 11-limit dichotic) in TAMNAMS.
Intervals
The generator (g) will fall between 343 cents (2\7 - two degrees of 7edo and 360 cents (3\10 - three degrees of 10edo), hence a neutral third.
2g, then, will fall between 686 cents (4\7) and 720 cents (3\5), the range of diatonic fifths.
The "large step" will fall between 171 cents (1\7) and 120 cents (1\10), ranging from a submajor second to a sinaic.
The "small step" will fall between 0 cents and 120 cents, sometimes sounding like a minor second, and sometimes sounding like a quartertone or smaller microtone.
The most frequent interval, then is the neutral third (and its inversion, the neutral sixth), followed by the perfect fourth and fifth. Thus, 7+3 combines the familiar sound of perfect fifths and fourths with the unfamiliar sounds of neutral intervals. They are compatible with Arabic and Turkish scales, but not with traditional Western ones.
Note: In TAMNAMS, a k-step interval class in dicotonic may be called a "k-step", "k-mosstep", or "k-dicostep". 1-indexed terms such as "mos(k+1)th" are discouraged for non-diatonic mosses.
# generators up | Notation (1/1 = 0) | name | In L's and s's | # generators up | Notation of 2/1 inverse | name | In L's and s's |
---|---|---|---|---|---|---|---|
The 10-note MOS has the following intervals (from some root): | |||||||
0 | 0 | perfect unison | 0 | 0 | 0 | perfect 10-step | 7L+3s |
1 | 7 | perfect 7-step | 5L+2s | -1 | 3 | perfect 3-step | 2L+1s |
2 | 4 | major 4-step | 3L+1s | -2 | 6 | minor 6-step | 4L+2s |
3 | 1 | major (1-)step | 1L | -3 | 9v | minor 9-step | 6L+3s |
4 | 8 | major 8-step | 6L+2s | -4 | 2v | minor 2-step | 1L+1s |
5 | 5 | major 5-step | 4L+1s | -5 | 5v | minor 5-step | 3L+2s |
6 | 2 | major 2-step | 2L | -6 | 8v | minor 8-step | 5L+3s |
7 | 9 | major 9-step | 7L+2s | -7 | 1v | minor (1-)step | 1s |
8 | 6^ | major 6-step | 5L+1s | -8 | 4v | minor 4-step | 2L+2s |
9 | 3^ | augmented 3-step | 3L | -9 | 7v | diminished 7-step | 4L+3s |
10 | 0^ | augmented unison | 1L-1s | -10 | 0v | diminished 10-step | 6L+4s |
11 | 7^ | augmented 7-step | 6L+1s | -11 | 3v | diminished 3-step | 1L+2s |
The chromatic 17-note MOS (either 7L 10s, 10L 7s, or 17edo) also has the following intervals (from some root): | |||||||
12 | 4^ | augmented 4-step | 4L | -12 | 6v | diminished 6-step | 3L+3s |
13 | 1^ | augmented (1-)step | 2L-1s | -13 | 9w | diminished 9-step | 5L+4s |
14 | 8^ | augmented 8-step | 8L+1s | -14 | 2w | diminished 2-step | 2s |
15 | 5^ | augmented 5-step | 5L | -15 | 5w | diminished 5-step | 2L+3s |
16 | 2^ | augmented 2-step | 3L-1s | -16 | 8w | diminished 8-step | 4L+4s |
Scale tree
The generator range reflects two extremes: one where L = s (3\10), and another where s = 0 (2\7). Between these extremes, there is an infinite continuum of possible generator sizes. By taking freshman sums of the two edges (adding the numerators, then adding the denominators), we can fill in this continuum with compatible edos, increasing in number of tones as we continue filling in the in-betweens. Thus, the smallest in-between edo would be (3+2)\(10+7) = 5\17 – five degrees of 17edo:
Generator | Cents | L | s | L/s | Comments | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Chroma-positive | Chroma-negative | ||||||||||
7\10 | 840.000 | 360.000 | 1 | 1 | 1.000 | ||||||
40\57 | 842.105 | 357.895 | 6 | 5 | 1.200 | Restles↑ | |||||
33\47 | 842.553 | 357.447 | 5 | 4 | 1.250 | ||||||
59\84 | 842.857 | 357.143 | 9 | 7 | 1.286 | ||||||
26\37 | 843.243 | 356.757 | 4 | 3 | 1.333 | ||||||
71\101 | 843.564 | 356.436 | 11 | 8 | 1.375 | ||||||
45\64 | 843.750 | 356.250 | 7 | 5 | 1.400 | Beatles | |||||
64\91 | 843.956 | 356.044 | 10 | 7 | 1.428 | ||||||
19\27 | 844.444 | 355.556 | 3 | 2 | 1.500 | L/s = 3/2, suhajira/ringo | |||||
69\98 | 844.698 | 355.102 | 11 | 7 | 1.571 | ||||||
50\71 | 845.070 | 354.930 | 8 | 5 | 1.600 | ||||||
81\115 | 845.217 | 354.783 | 13 | 8 | 1.625 | Golden suhajira | |||||
31\44 | 845.455 | 354.545 | 5 | 3 | 1.667 | ||||||
74\105 | 845.714 | 354.286 | 12 | 7 | 1.714 | ||||||
43\61 | 845.902 | 354.098 | 7 | 4 | 1.750 | ||||||
55\78 | 846.154 | 353.846 | 9 | 5 | 1.800 | ||||||
12\17 | 847.059 | 352.941 | 2 | 1 | 2.000 | Basic dicotonic (Generators smaller than this are proper) | |||||
53\75 | 848.000 | 352.000 | 9 | 4 | 2.250 | ||||||
41\58 | 848.273 | 351.724 | 7 | 3 | 2.333 | ||||||
70\99 | 848.485 | 351.515 | 12 | 5 | 2.400 | Hemif/hemififths | |||||
29\41 | 848.780 | 351.220 | 5 | 2 | 2.500 | Mohaha/neutrominant | |||||
75\106 | 849.057 | 350.943 | 13 | 5 | 2.600 | Hemif/salsa/karadeniz | |||||
46\65 | 849.231 | 350.769 | 8 | 3 | 2.667 | Mohaha/mohamaq | |||||
63\89 | 849.438 | 350.562 | 11 | 4 | 2.750 | ||||||
17\24 | 850.000 | 350.000 | 3 | 1 | 3.000 | L/s = 3/1 | |||||
56\79 | 850.633 | 349.367 | 10 | 3 | 3.333 | ||||||
39\55 | 850.909 | 349.091 | 7 | 2 | 3.500 | ||||||
61\86 | 851.613 | 358.837 | 11 | 3 | 3.667 | ||||||
22\31 | 851.613 | 348.387 | 4 | 1 | 4.000 | Mohaha/migration/mohajira | |||||
49\69 | 852.174 | 347.826 | 9 | 2 | 4.500 | ||||||
27\38 | 852.632 | 347.368 | 5 | 1 | 5.000 | ||||||
32\45 | 853.333 | 346.667 | 6 | 1 | 6.000 | Mohaha/ptolemy | |||||
5\7 | 857.143 | 342.867 | 1 | 0 | → inf |
The scale produced by stacks of 5\17 is the 17edo neutral scale. Between 11/38 and 16/55, with 9/31 in between, is the mohajira/mohaha/mohoho range, where mohaha and mohoho use the MOS as the chromatic scale of a chromatic pair.
Other compatible edos include: 37edo, 27edo, 44edo, 41edo, 24edo, 31edo.
You can also build this scale by stacking neutral thirds that are not members of edos – for instance, frequency ratios 11:9, 49:40, 27:22, 16:13 – or the square root of 3:2 (a bisected just perfect fifth).
Rank-2 temperaments
7-note subsets
If you stop the chain at 7 tones, you have a heptatonic scale of the form 3L 4s:
L s s L s L s
The large steps here consist of t+s of the 10-tone system, and the small step is the same as t. Graham proposes calling the large step here T for "tone," uppercase because it is a wider tone than t. Thus, we have:
T t t T t T t
This scale (and its rotations) is not the only possible heptatonic scale. Graham also gives us:
T t t T t t T
which is not a complete moment of symmetry scale in itself, but a subset of one.
Tetrachordal structure
Due to the frequency of perfect fourths and fifths in this scale, it can also be analyzed as a tetrachordal scale. The perfect fourth can be traversed by 3 t's and a q, or 2 t's and a T.
I ( - Andrew Heathwaite) offer "a" to refer to a step of 2t (for "augmented second")
Thus, the possible tetrachords are:
T t t
t T t
t t T
a q t
a t q
t a q
t q a
q a t
q t a