7L 3s

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Scale structure
Step pattern LLLsLLsLLs
sLLsLLsLLL
Equave 2/1 (1200.0¢)
Period 2/1 (1200.0¢)
Generator size
Bright 7\10 to 5\7 (840.0¢ to 857.1¢)
Dark 2\7 to 3\10 (342.9¢ to 360.0¢)
Related MOS scales
Parent 3L 4s
Sister 3L 7s
Daughters 10L 7s, 7L 10s
Neutralized 4L 6s
2-Flought 17L 3s, 7L 13s
Equal tunings
Equalized (L:s = 1:1) 7\10 (840.0¢)
Supersoft (L:s = 4:3) 26\37 (843.2¢)
Soft (L:s = 3:2) 19\27 (844.4¢)
Semisoft (L:s = 5:3) 31\44 (845.5¢)
Basic (L:s = 2:1) 12\17 (847.1¢)
Semihard (L:s = 5:2) 29\41 (848.8¢)
Hard (L:s = 3:1) 17\24 (850.0¢)
Superhard (L:s = 4:1) 22\31 (851.6¢)
Collapsed (L:s = 1:0) 5\7 (857.1¢)

7L 3s is a 2/1-equivalent (octave-equivalent) moment of symmetry scale containing 7 large steps and 3 small steps, repeating every octave. Generators that produce this scale range from 840¢ to 857.1¢, or from 342.9¢ to 360¢. 7L 3s represents temperaments such as mohajira/mohaha/mohoho, among others, whose generators are around a neutral 3rd. The seven and ten-note forms of mohaha/mohoho form a chromatic pair.

Name

TAMNAMS suggests the temperament-agnostic name dicoid as the name of 7L 3s. The name derives from dichotic and dicot temperament. Although this name is directly based off of a temperament, tunings of dichotic and dicot cover the entire tuning range of 7L 3s; see TAMNAMS/Appendix #Dicoid (7L 3s) for more information.

Scale properties

Intervals

The intervals of 7L 3s are named after the number of mossteps (L and s) they subtend. Each interval, apart from the root and octave (perfect 0-mosstep and perfect 10-mosstep), has two varieties, or sizes, each. Interval varieties are named major and minor for the large and small sizes, respectively, and augmented, perfect, and diminished for the scale's generators.

Intervals of 7L 3s
Intervals Steps
subtended
Range in cents
Generic Specific Abbrev.
0-mosstep Perfect 0-mosstep P0ms 0 0.0¢
1-mosstep Minor 1-mosstep m1ms s 0.0¢ to 120.0¢
Major 1-mosstep M1ms L 120.0¢ to 171.4¢
2-mosstep Minor 2-mosstep m2ms L + s 171.4¢ to 240.0¢
Major 2-mosstep M2ms 2L 240.0¢ to 342.9¢
3-mosstep Perfect 3-mosstep P3ms 2L + s 342.9¢ to 360.0¢
Augmented 3-mosstep A3ms 3L 360.0¢ to 514.3¢
4-mosstep Minor 4-mosstep m4ms 2L + 2s 342.9¢ to 480.0¢
Major 4-mosstep M4ms 3L + s 480.0¢ to 514.3¢
5-mosstep Minor 5-mosstep m5ms 3L + 2s 514.3¢ to 600.0¢
Major 5-mosstep M5ms 4L + s 600.0¢ to 685.7¢
6-mosstep Minor 6-mosstep m6ms 4L + 2s 685.7¢ to 720.0¢
Major 6-mosstep M6ms 5L + s 720.0¢ to 857.1¢
7-mosstep Diminished 7-mosstep d7ms 4L + 3s 685.7¢ to 840.0¢
Perfect 7-mosstep P7ms 5L + 2s 840.0¢ to 857.1¢
8-mosstep Minor 8-mosstep m8ms 5L + 3s 857.1¢ to 960.0¢
Major 8-mosstep M8ms 6L + 2s 960.0¢ to 1028.6¢
9-mosstep Minor 9-mosstep m9ms 6L + 3s 1028.6¢ to 1080.0¢
Major 9-mosstep M9ms 7L + 2s 1080.0¢ to 1200.0¢
10-mosstep Perfect 10-mosstep P10ms 7L + 3s 1200.0¢

Generator chain

A chain of bright generators, each a perfect 7-mosstep, produces the following scale degrees. A chain of 10 bright generators contains the scale degrees of one of the modes of 7L 3s. Expanding the chain to 17 scale degrees produces the modes of either 10L 7s (for soft-of-basic tunings) or 7L 10s (for hard-of-basic tunings).

Generator chain of 7L 3s
Bright gens Scale Degree - 16 Augmented 2-mosdegree A2md
15 Augmented 5-mosdegree A5md
14 Augmented 8-mosdegree A8md
13 Augmented 1-mosdegree A1md
12 Augmented 4-mosdegree A4md
11 Augmented 7-mosdegree A7md
10 Augmented 0-mosdegree A0md
9 Augmented 3-mosdegree A3md
8 Major 6-mosdegree M6md
7 Major 9-mosdegree M9md
6 Major 2-mosdegree M2md
5 Major 5-mosdegree M5md
4 Major 8-mosdegree M8md
3 Major 1-mosdegree M1md
2 Major 4-mosdegree M4md
1 Perfect 7-mosdegree P7md
0 Perfect 0-mosdegree
Perfect 10-mosdegree
P0md
P10md
-1 Perfect 3-mosdegree P3md
-2 Minor 6-mosdegree m6md
-3 Minor 9-mosdegree m9md
-4 Minor 2-mosdegree m2md
-5 Minor 5-mosdegree m5md
-6 Minor 8-mosdegree m8md
-7 Minor 1-mosdegree m1md
-8 Minor 4-mosdegree m4md
-9 Diminished 7-mosdegree d7md
-10 Diminished 10-mosdegree d10md
-11 Diminished 3-mosdegree d3md
-12 Diminished 6-mosdegree d6md
-13 Diminished 9-mosdegree d9md
-14 Diminished 2-mosdegree d2md
-15 Diminished 5-mosdegree d5md
-16 Diminished 8-mosdegree d8md

Modes

Scale degrees of the modes of 7L 3s 
UDP Cyclic
order
Step
pattern
Scale degree (mosdegree)
0 1 2 3 4 5 6 7 8 9 10
9|0 1 LLLsLLsLLs Perf. Maj. Maj. Aug. Maj. Maj. Maj. Perf. Maj. Maj. Perf.
8|1 8 LLsLLLsLLs Perf. Maj. Maj. Perf. Maj. Maj. Maj. Perf. Maj. Maj. Perf.
7|2 5 LLsLLsLLLs Perf. Maj. Maj. Perf. Maj. Maj. Min. Perf. Maj. Maj. Perf.
6|3 2 LLsLLsLLsL Perf. Maj. Maj. Perf. Maj. Maj. Min. Perf. Maj. Min. Perf.
5|4 9 LsLLLsLLsL Perf. Maj. Min. Perf. Maj. Maj. Min. Perf. Maj. Min. Perf.
4|5 6 LsLLsLLLsL Perf. Maj. Min. Perf. Maj. Min. Min. Perf. Maj. Min. Perf.
3|6 3 LsLLsLLsLL Perf. Maj. Min. Perf. Maj. Min. Min. Perf. Min. Min. Perf.
2|7 10 sLLLsLLsLL Perf. Min. Min. Perf. Maj. Min. Min. Perf. Min. Min. Perf.
1|8 7 sLLsLLLsLL Perf. Min. Min. Perf. Min. Min. Min. Perf. Min. Min. Perf.
0|9 4 sLLsLLsLLL Perf. Min. Min. Perf. Min. Min. Min. Dim. Min. Min. Perf.

Theory

Neutral intervals

7L 3s combines the familiar sound of perfect fifths and fourths with the unfamiliar sounds of neutral intervals, thus making it compatible with Arabic and Turkish scales, but not with traditional Western scales. Notable intervals include:

  • The perfect 3-mosstep, the scale's dark generator, whose range is around that of a neutral third.
  • The perfect 7-mosstep, the scale's bright generator, the inversion of the perfect 3-mosstep, whose range is around that of a neutral sixth.
  • The minor mosstep, or small step, which ranges form a quartertone to a minor second.
  • The major mosstep, or large step, which ranges from a submajor second to a sinaic, or trienthird (around 128¢).
  • The major 4-mosstep, whose range coincides with that of a perfect fourth.
  • The minor 6-mosstep, the inversion of the major 4-mosstep, whose range coincides with that of a perfect 5th.

Quartertone and tetrachordal analysis

Due to the presence of quartertone-like intervals, Graham Breed has proposed the terms tone (abbreviated as t) and quartertone (abbreviated as q) as alternatives for large and small steps. This interpretation only makes sense for step ratios in which the small step approximates a quartertone. Additionally, Breed has also proposed a larger tone size, abbreviated using a capital T, to refer to the combination of t and q. Through this addition of a larger step, 7-note subsets of 7L 3s can be constructed. Some of these subsets are identical to that of 3L 4s, such as T-t-T-t-T-t-t, but Breed states that non-MOS patterns are possible, such as T-t-t-T-t-t-T.

Additionally, due to the presence of fourth and fifth-like intervals, 7L 3s can be analyzed as a tetrachordal scale. Since the major 4-dicostep, the fourth-like interval, is reached using 4 steps rather than 3 (3 tones and 1 quartertone), Andrew Heathwaite offers an additional step A, for augmented second, to refer to the combination of two tones (t). Thus, the possible tetrachords can be built as a combination of a (large) tone and two (regular) tones (T-t-t), or an augmented step, small tone, and quartertone (A-t-q).

Scale tree

Scale Tree and Tuning Spectrum of 7L 3s
Generator(edo) Cents Step ratio Comments
Bright Dark L:s Hardness
7\10 840.000 360.000 1:1 1.000 Equalized 7L 3s
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 Supersoft 7L 3s
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 1.429
19\27 844.444 355.556 3:2 1.500 Soft 7L 3s
Suhajira / ringo
69\98 844.898 355.102 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 Semisoft 7L 3s
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 7L 3s
Scales with tunings softer than this are proper
53\75 848.000 352.000 9:4 2.250
41\58 848.276 351.724 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 Semihard 7L 3s
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 Hard 7L 3s
56\79 850.633 349.367 10:3 3.333
39\55 850.909 349.091 7:2 3.500
61\86 851.163 348.837 11:3 3.667
22\31 851.613 348.387 4:1 4.000 Superhard 7L 3s
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\7 857.143 342.857 1:0 → ∞ Collapsed 7L 3s

External links