Semicanousma
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| Ratio | 14641/14580 |
| Factorization | 2-2 × 3-6 × 5-1 × 114 |
| Monzo | [-2 -6 -1 0 4⟩ |
| Size in cents | 7.2280504¢ |
| Name | semicanousma |
| Color name | 1o4g1, quadlo-agu unison |
| FJS name | [math]\text{dd1}^{11,11,11,11}_{5}[/math] |
| Special properties | reduced |
| Tenney height (log2 nd) | 27.6694 |
| Weil height (log2 max(n, d)) | 27.6755 |
| Wilson height (sopfr(nd)) | 71 |
| Harmonic entropy (Shannon, [math]\sqrt{nd}[/math]) |
~1.67269 bits |
| Comma size | small |
| open this interval in xen-calc | |
The semicanousma, 14641/14580 = [-2 -6 -1 0 4⟩, is an 11-limit comma measuring about 7.2 cents, named for the fact that it is one of the commas tempered out in the semicanou temperament. It is the amount by which a stack of four Alpharabian artoneutral thirds (11/9) exceeds the ptolemaic ninth (20/9). It is also the difference between 121/120 (biyatisma) and 243/242 (rastma).
Temperaments
Tempering it out leads to the rank-4 semicanousmic temperament, which splits the syntonic comma into two equal parts, each representing 121/120~243/242, so the comma can be said to be the undecimal counterpart of both hemimean and canousma. It also identifies 20/11 by three 11/9's stacked, so an octave is divided into 11/9-11/9-11/9-11/10.
See also
- Rank-4 temperament #Semicanousmic (14641/14580)
- Semicanousmic clan, the clan of rank-3 temperaments where it is tempered out
- Small comma