↖ 1L 4s ↑ 2L 4s 3L 4s ↗
← 1L 5s 2L 5s 3L 5s →
↙ 1L 6s ↓ 2L 6s 3L 6s ↘
┌╥┬┬╥┬┬┬┐
│║││║││││
│││││││││
└┴┴┴┴┴┴┴┘
Scale structure
Step pattern LssLsss
sssLssL
Equave 2/1 (1200.0 ¢)
Period 2/1 (1200.0 ¢)
Generator size
Bright 3\7 to 1\2 (514.3 ¢ to 600.0 ¢)
Dark 1\2 to 4\7 (600.0 ¢ to 685.7 ¢)
TAMNAMS information
Name antidiatonic
Prefix pel-
Abbrev. pel
Related MOS scales
Parent 2L 3s
Sister 5L 2s
Daughters 7L 2s, 2L 7s
Neutralized 4L 3s
2-Flought 9L 5s, 2L 12s
Equal tunings
Equalized (L:s = 1:1) 3\7 (514.3 ¢)
Supersoft (L:s = 4:3) 10\23 (521.7 ¢)
Soft (L:s = 3:2) 7\16 (525.0 ¢)
Semisoft (L:s = 5:3) 11\25 (528.0 ¢)
Basic (L:s = 2:1) 4\9 (533.3 ¢)
Semihard (L:s = 5:2) 9\20 (540.0 ¢)
Hard (L:s = 3:1) 5\11 (545.5 ¢)
Superhard (L:s = 4:1) 6\13 (553.8 ¢)
Collapsed (L:s = 1:0) 1\2 (600.0 ¢)

2L 5s, named antidiatonic in TAMNAMS, is a 2/1-equivalent (octave-equivalent) moment of symmetry scale containing 2 large steps and 5 small steps, repeating every octave. Generators that produce this scale range from 514.3 ¢ to 600 ¢, or from 600 ¢ to 685.7 ¢.

Name

TAMNAMS suggests the temperament-agnostic name antidiatonic for this scale, adopted from the common use of the term to refer to diatonic (5L 2s) but with the large and small steps switched.

Notation

This article assumes TAMNAMS for naming step ratios, intervals, and scale degrees, and diamond-MOS notation for note names.

Intervals and degrees

Names for this scale's intervals (mossteps) and scale degrees (mosdegrees) are based on the number of large and small steps from the root, starting at 0 (0-mosstep and 0-mosdegree) for the unison, per TAMNAMS. Ordinal names, such as mos-1st for the unison, are discouraged for non-diatonic MOS scales.

Being a moment-of-symmetry scale, every interval class of 2L 5s, except for the unison and octave, has two varieties – large and small – whose relative qualities are denoted as major or minor, or augmented, perfect, and diminished for the generators.

Intervals of 2L 5s
Intervals Steps
subtended
Range in cents
Generic Specific Abbrev.
0-pelstep Perfect 0-pelstep P0pels 0 0.0 ¢
1-pelstep Minor 1-pelstep m1pels s 0.0 ¢ to 171.4 ¢
Major 1-pelstep M1pels L 171.4 ¢ to 600.0 ¢
2-pelstep Minor 2-pelstep m2pels 2s 0.0 ¢ to 342.9 ¢
Major 2-pelstep M2pels L + s 342.9 ¢ to 600.0 ¢
3-pelstep Diminished 3-pelstep d3pels 3s 0.0 ¢ to 514.3 ¢
Perfect 3-pelstep P3pels L + 2s 514.3 ¢ to 600.0 ¢
4-pelstep Perfect 4-pelstep P4pels L + 3s 600.0 ¢ to 685.7 ¢
Augmented 4-pelstep A4pels 2L + 2s 685.7 ¢ to 1200.0 ¢
5-pelstep Minor 5-pelstep m5pels L + 4s 600.0 ¢ to 857.1 ¢
Major 5-pelstep M5pels 2L + 3s 857.1 ¢ to 1200.0 ¢
6-pelstep Minor 6-pelstep m6pels L + 5s 600.0 ¢ to 1028.6 ¢
Major 6-pelstep M6pels 2L + 4s 1028.6 ¢ to 1200.0 ¢
7-pelstep Perfect 7-pelstep P7pels 2L + 5s 1200.0 ¢

Note names

For this article, note names are based on diamond-MOS notation, where the naturals JKLMNOP are applied to the step pattern sLsssLs and the accidentals & (pronounced "am" or "amp") and @ (pronounced "at") are used to represent sharps and flats respectively. Thus, the basic gamut for 2L 5s is the following:

J, K, K&/L@, L, M, N, O, O&/P@, P, J

Theory

Antidiatonic is similar to diatonic (5L 2s) except interval classes are flipped. For example, there are natural, harmonic, and melodic major scales instead of minor scales, and its locrian scale, called "antilocrian", has an augmented "fifth" instead of a diminished fifth. The flatter the "fifth" (or 4-mosstep) gets, the less the scale resembles diatonic. Additionally, there are temperaments associated with this MOS, such as score, that do not have intervals that resemble a diatonic 5th, flattened or otherwise.

Low harmonic entropy scales

There is one notable harmonic entropy minimum: Liese/triton, in which the generator is 7/5 (582.5¢) and three of them make a 3/1 (1902¢).

Temperament interpretations

2L 5s has several rank-2 temperament interpretations, such as:

  • Score, with generators around 540.1¢.
  • Liese, with generators around 632.4¢.
  • Mavila, with generators around 679.8¢.

Modes

Modes of the antidiatonic scale are usually named as "anti-" combined with the opposite mode of the diatonic scale, e.g. 4|2 being called "antiaeolian". CompactStar also gave original names based on regions of France to mirror how modes of the diatonic scale are named on regions of Greece and Turkey.


Modes of 2L 5s
UDP Cyclic
order
Step
pattern
6|0 1 LssLsss
5|1 4 LsssLss
4|2 7 sLssLss
3|3 3 sLsssLs
2|4 6 ssLssLs
1|5 2 ssLsssL
0|6 5 sssLssL

Scale tree

Generator ranges:

  • Chroma-positive generator: 514.2857 cents (3\7) to 600 cents (1\2)
  • Chroma-negative generator: 600 cents (1\2) to 685.7143 cents (4\7)
Generator Cents L s L/s Comments
3\7 514.286 1 1 1.000
16\37 518.919 6 5 1.200 Gravity
13\30 520.000 5 4 1.250
23\53 520.755 9 7 1.286
10\23 521.739 4 3 1.333
27\62 522.581 11 8 1.375
17\39 523.077 7 5 1.400
24\55 523.636 10 7 1.428
7\16 525.000 3 2 1.500 Mavila is in this region
25\57 526.316 11 7 1.571
18\41 526.829 8 5 1.600
29\66 527.273 13 8 1.625 Golden mavila (527.1497¢)
11\25 528.000 5 3 1.667
26\59 528.814 12 7 1.714
15\34 529.412 7 4 1.750
19\43 530.233 9 5 1.800 Mabila / Amavil
4\9 533.333 2 1 2.000 Basic antidiatonic
(Generators smaller than this are proper)
17\38 536.842 9 4 2.250
13\29 537.931 7 3 2.333
22\49 538.776 12 5 2.400
9\20 540.000 5 2 2.500 Score
23\51 541.176 13 5 2.600 Unnamed golden tuning (541.3837¢)
14\31 541.935 8 3 2.667 Casablanca is around here
19\42 542.857 11 4 2.750
5\11 545.455 3 1 3.000
16\35 548.571 10 3 3.333
11\24 550.000 7 2 3.500
17\37 551.351 11 3 3.667 Freivald / emka
6\13 553.846 4 1 4.000
13\28 557.143 9 2 4.500
7\15 560.000 5 1 5.000 Thuja is around here
8\17 564.706 6 1 6.000 Liese↓, triton
1\2 600.000 1 0 → inf