Mohajira[note 1] is a meantone temperament that splits 3/2 into two 11/9 generators and the 6/5 into two 11/10's, thus equating 11/10 with 12/11 and 11/9 with 27/22. As a result, eight 11/9's reach 5/4, and five reach 11/8. It tempers out the biyatisma (121/120) and the rastma (along with meantone's syntonic comma). It can be thought of as meantone with quartertones as it merely splits the generator 3/2 into two equally spaced neutral thirds. Among the most common is the 7-note mos Mohajira[7] which consists of the steps LsLsLss, as well as the modmos "Rast" which merely flats the fourth by one quartertone.

Mohajira
Subgroups 2.3.5.7, 2.3.5.7.11
Comma basis 81/80, 6144/6125 (7-limit);
81/80, 121/120, 176/175 (11-limit)
Reduced mapping ⟨1; 2 8 -11 5]
ET join 24 & 31
Generators (CWE) ~11/9 = 348.5 ¢
MOS scales 3L 4s, 7L 3s, 7L 10s, 7L 17s
Ploidacot dicot
Minimax error 9-odd-limit: 10.8 ¢;
11-limit 21-odd-limit: 10.8 ¢
Target scale size 9-odd-limit: 24 notes;
11-limit 21-odd-limit: 24 notes

The simplest form of this temperament, in 2.3.5.11, is sometimes called mohaha. To extend mohaha into full 11-limit mohajira, 7 is found at 11 neutral thirds down, tempering out the valinorsma such that 14/11 is equated with 32/25. Mohaha is tuned best sharp of 31edo's neutral third. An alternate extension, migration, is optimized for flatter tunings and finds 7 at 20 generators up, the same mapping as in septimal meantone which tempers out 225/224.

As mohajira is a neutral third system, 13 also has a reasonable mapping at −1 generator, equating 11/9 and 16/13. Subsequently, 17 is mapped to −10 generators (the diatonic semitone) and 19 to −6 generators (the minor third).

For technical data, see Meantone family #Mohajira.

Interval chain

In the following tables, odd harmonics 1–11 are shown in bold.

# Cents* Approximate ratios
0 0.0 1/1
1 348.5 11/9, 27/22
2 697.0 3/2
3 1045.5 11/6, 20/11
4 194.0 9/8, 10/9
5 542.5 11/8, 15/11
6 890.9 5/3
7 39.4 33/32, 36/35, 45/44,
55/54, 64/63
8 387.9 5/4
9 736.4 32/21
10 1084.9 15/8
11 233.4 8/7
12 581.9 25/18, 45/32
13 930.4 12/7
14 78.9 22/21, 25/24
15 427.4 9/7
16 775.9 11/7
17 1124.3 27/14, 40/21
# Cents* Approximate ratios
0 1200.0 2/1
-1 851.5 18/11, 44/27
-2 503.0 4/3
-3 154.5 11/10, 12/11
-4 1006.0 9/5, 16/9
-5 657.5 16/11, 22/15
-6 309.1 6/5
-7 1160.6 35/18, 63/32, 64/33,
88/45, 108/55
-8 812.1 8/5
-9 463.6 21/16
-10 115.1 16/15
-11 966.6 7/4
-12 618.1 36/25, 64/45
-13 269.6 7/6
-14 1121.1 21/11, 48/25
-15 772.6 14/9
-16 424.1 14/11
-17 75.7 21/20, 28/27

* In 11-limit CWE tuning, octave reduced

Scales and harmony

There are seven modes of mohajira's 7-note mos (named mosh due to being "mohajira-ish") which are structured in an analogous way to the seven modes of the major scale. They can be thought of as quarter tone altered modes in a 24edo setting, but also as microtonal altered scales in any equal temperament. While the Mohajira[7] mos by itself is quite beautiful, the modMOS Rast tends to be more expressive as it contains a few major and minor thirds allowing for more contrast.

Tunings

7-limit norm-based tunings
Euclidean
Constrained Constrained & skewed Destretched
Tenney CTE: ~128/105 = 348.4374 ¢ CWE: ~128/105 = 348.4194 ¢ POTE: ~128/105 = 348.4149 ¢
11-limit norm-based tunings
Euclidean
Constrained Constrained & skewed Destretched
Tenney CTE: ~11/9 = 348.5608 ¢ CWE: ~11/9 = 348.4910 ¢ POTE: ~11/9 = 348.4767 ¢

Notes

  1. (/mʊˈhɑːdʒɪɹə, -hæ-/ muu-HA(H)-jirr-ə or /məˈhɑːdʒɪɹə, -hæ-/ mə-HA(H)-jirr-ə, named by Jacques Dudon from Arabic مهاجرة Muhājirah)