83521/83486

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Interval information
Ratio 83521/83486
Subgroup monzo 2.13.17.19 [-1 -3 4 -1
Size in cents 0.72563656¢
Name crawma
Color name 19u17o43u32, nuquadso-atrithu 2nd,
Nuquadso-atrithu comma
FJS name [math]\text{m2}^{17,17,17,17}_{13,13,13,19}[/math]
Special properties reduced
Tenney height (log2 nd) 32.6991
Weil height (log2 max(n, d)) 32.6997
Wilson height (sopfr (nd)) 128
Harmonic entropy
(Shannon, [math]\sqrt{nd}[/math])
~1.20474 bits
Comma size unnoticeable
open this interval in xen-calc

83521/83486, known as the crawma, is a 19-limit (more precisely, 2.17/13.19/13 subgroup) unnoticeable comma. It forms the difference between a stack of four 17/13's and a stack of one octave and one 19/13.

Temperaments

Tempering out this comma in the 19-limit leads to the rank-7 crawmic temperament, or in the 2.17/13.19/13 subgroup, the rank-2 crawic temperament generated by a tempered 17/13. 31edo's 12\31 = 464.516¢ is the first generator to tune crawic accurately, with 17/13, 19/13, and 19/17 respectively having errors +0.088¢, +1.079¢, and +0.991¢. The CTE generator of crawic temperament, 464.236¢, is extremely well-approximated by 53\137 = 464.234¢.

Terminology

The name crawma was proposed by groundfault as a more distinctive-sounding crow-themed name for the comma than "cawma". The word craw has an archaic sense 'to caw, to croak, to crow'.

See also