4L 2s

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↖3L 1s↑4L 1s 5L 1s↗
←3L 2s4L 2s5L 2s→
↙3L 3s↓4L 3s 5L 3s↘
Brightest mode LLsLLs
Period 1\2
Range for bright generator 1\6 (200¢) to 1\4 (300¢)
Range for dark generator 1\4 (300¢) to 2\6 (400¢)
TAMNAMS name citric
TAMNAMS prefix citro- (abbr. cit)
Parent MOS 2L 2s
Sister MOS 2L 4s
Daughter MOSes 6L 4s, 4L 6s
Equal tunings
Supersoft (L:s = 4:3) 4\22 (218.2¢)
Soft (L:s = 3:2) 3\16 (225¢)
Semisoft (L:s = 5:3) 5\26 (230.8¢)
Basic (L:s = 2:1) 2\10 (240¢)
Semihard (L:s = 5:2) 5\24 (250¢)
Hard (L:s = 3:1) 3\14 (257.1¢)
Superhard (L:s = 4:1) 4\18 (266.7¢)

4L 2s, also called citric, is a moment of symmetry scale consisting of 4 large steps and 2 small steps, with a period of 2 large steps and 1 small step that repeats twice every octave, or every 600¢. This scale is made using a generator ranging from 200¢ to 300¢, or from 300¢ to 400¢.

This MOS resembles 5L 2s, but with one large step removed.

There are three scales with this MOS pattern that are significant minima of harmonic entropy. The first is antikythera, or no-3's srutal/pajara, which is srutal/pajara without any intervals containing 3 in their prime factorization, so it becomes a 2.5.9 or 2.5.7.9 subgroup temperament. This means that the generator is twice that of srutal/pajara (210-220 cents rather than 105-110), since odd numbers of generators are only needed for intervals with 3. So this is a basically "whole tone" scale, but made uneven so some 2-step intervals are 5/4 and others are 9/7.

The second is decimal, in which two generators make a 4/3, and the third is Doublewide, in which the generator is 7/6 so the period minus the generator is 6/5.

In addition to the true MOS with pattern LLsLLs, all these scales also come in a near-MOS version, LLLsLs, in which the period is the only generic interval that has more than two specific representatives. The true MOS is always proper, but the near-MOS is only proper if the generator is smaller than 2\10 of an octave (240 cents).

Modes

Modes of 4L 2s
UDP Step pattern
4|0 LLsLLs
2|2 LsLLsL
0|4 sLLsLL

Scale tree

Generator Cents Comments
1\6 200
6\34 211.76
5\28 214.29 Antikythera is around here
4\22 218.18
3\16 225
227.56
8\42 228.57
600/(1+phi) Golden lemba
13\68 229.41
5\26 230.77
232.8
7\36 233.33 Lemba is around here
2\10 240 Boundary of propriety for near-MOS

Optimum rank range (L/s=2/1) for MOS

5\24 250 Decimal is around here
251.89
8\38 252.63
253.39 L/s = e
3\14 257.14 L/s = 3
258.81 L/s = pi
4\18 266.67 L/s = 4
5\22 272.73
6\26 276.92 Doublewide is around here
7\30 280
8\34 282.35
9\38 284.21
10\42 285.71
11\46 286.96
1\4 300