4L 4s

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↖3L 3s↑4L 3s 5L 3s↗
←3L 4s4L 4s5L 4s→
↙3L 5s↓4L 5s 5L 5s↘
Brightest mode LsLsLsLs
Period 1\4
Range for bright generator 1\8 (150¢) to 1\4 (300¢)
Range for dark generator 0\4 (0¢) to 1\8 (150¢)
TAMNAMS name tetrawood; diminished
TAMNAMS prefix tetrawd- (abbr. ttw)
Parent MOS none
Sister MOS 4L 4s
Daughter MOSes 8L 4s, 4L 8s
Equal tunings
Supersoft (L:s = 4:3) 4\28 (171.4¢)
Soft (L:s = 3:2) 3\20 (180¢)
Semisoft (L:s = 5:3) 5\32 (187.5¢)
Basic (L:s = 2:1) 2\12 (200¢)
Semihard (L:s = 5:2) 5\28 (214.3¢)
Hard (L:s = 3:1) 3\16 (225¢)
Superhard (L:s = 4:1) 4\20 (240¢)

4L 4s, also called tetrawood or diminished, is a moment of symmetry scale consisting of 4 large steps and 4 small steps, with a period of 1 large step and 1 small step that repeats 4 times every octave, or every 300¢. This scale is made using a generator ranging from 150¢ to 300¢, or from 0¢ to 150¢.

The minimum harmonic entropy scale with this MOS pattern is diminished[8], basically the familiar octatonic scale of 12edo.

There are 4 different near-MOSes such that multiples of the period are the only generic intervals with more than two specific representatives: LLsLsLss, LLsLssLs, LLssLLss, LLssLsLs. However, none are strictly proper in 12edo. (They are only proper if the generator is larger than 100 cents, which unfortunately is the wrong direction for good diminished tunings.)

Scale tree

Generator Cents L s L/s Comments
Chroma-positive Chroma-negative
1\8 150.000 150.000 1 1 1.000
6\44 163.636 136.364 6 5 1.200 Fourfives↑
5\36 166.667 133.333 5 4 1.250
9\64 168.750 105.000 9 7 1.286
4\28 171.429 128.571 4 3 1.333
11\76 173.684 126.316 11 8 1.375
7\48 175.000 125.000 7 5 1.400
10\68 176.471 123.529 10 7 1.428
3\20 180.000 60.000 3 2 1.500 L/s = 3/2
11\72 183.333 116.667 11 7 1.571
8\52 184.615 115.385 8 5 1.600
13\84 185.714 114.286 13 8 1.625 Golden diminished
5\32 187.500 112.500 5 3 1.667
12\76 189.474 110.526 12 7 1.714
7\44 190.909 109.091 7 4 1.750
9\56 192.857 107.143 9 5 1.800
2\12 200.000 100.000 2 1 2.000 Basic tetrawood
Diminished is optimal around here
9\52 207.692 92.308 9 4 2.250
7\40 210.000 90.000 7 3 2.333
12\68 211.765 88.235 12 5 2.400
5\28 214.286 85.714 5 2 2.500
13\72 216.667 83.333 13 5 2.600 Unnamed golden tuning
8\44 218.182 81.818 8 3 2.667
11\60 220.000 80.000 11 4 2.750
3\16 225.000 75.000 3 1 3.000 L/s = 3/1
10\52 230.769 69.231 10 3 3.333
7\36 233.333 66.667 7 2 3.500
11\56 235.714 64.286 11 3 3.667
4\20 240.000 60.000 4 1 4.000
9\44 245.455 54.545 9 2 4.500
5\24 250.000 50.000 5 1 5.000
6\28 257.143 42.857 6 1 6.000 Quadritikleismic↓
1\4 300.000 0.000 1 0 → inf