Crawma
| 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'.