Semicanousma

Interval information

Ratio	14641/14580
Factorization	2-2 × 3-6 × 5-1 × 114
Monzo	[-2 -6 -1 0 4⟩
Size in cents	7.22805¢
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
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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