Nanisma
Interval information |
reduced subharmonic
(Shannon, [math]\displaystyle{ \sqrt{nd} }[/math])
The nanisma (monzo: [109 -67 0 -1⟩) is an unnoticeable 7-limit (also 2.3.7-subgroup) comma measuring about 0.189 cents. It is the tiny interval between the pythagorean ratio [107 -67⟩ and the harmonic minor seventh of ratio 7/4.
The nanisma is considered as a 3=7 xenharmonic bridge. It also describes the difference between [108 -68⟩ (a stack of four 17-commas) and the septimal minor third of ratio 7/6, and also the difference between [-109 69⟩ and the wide septimal major third of ratio 9/7. It can also be thought of as the difference between Mercator's comma and the garischisma.
Temperaments
The nanisma is tempered out in such notable edos as 306, 612, 1277, 1583, 2860, 4137, 4802, 5414, 6079, 6691, 11493, 12105, and 12770, leading to the nanismic temperament, in which sixty-seven fifths make up a septimal whole tone 8/7 with octave reduction.
Nanic
See Very high accuracy temperaments #Nanic.
Nanismic
Subgroup: 2.3.5.7
Comma list: [109 -67 0 -1⟩
Mapping: [⟨1 0 0 109], ⟨0 1 0 -67], ⟨0 0 1 0]]
- sval mapping generators: ~2, ~3, ~5
Optimal tuning (CTE): ~2 = 1200.0000, ~3/2 = 701.9578, ~5/4 = 386.3137
Optimal ET sequence: 53, 147d, 200, 253, 306c, 359, 412, 506d, 559, 612, 1277, 1889, 3525, 4137, 4190, 4802, 5414, 6079, 6691, 18184, 24875, 92809, 117684, 142559
Badness: 6.09 × 10-3
Etymology
This comma was named by Margo Schulter in 2002[1].