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Interval information
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).


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