91/90

Interval information

Ratio	91/90
Factorization	2-1 × 3-2 × 5-1 × 7 × 13
Monzo	[-1 -2 -1 1 0 1⟩
Size in cents	19.12985¢
Names	biome comma, superleap comma
Color name	3ozg2, thozogu 2nd, Thozogu comma
FJS name	[math]\displaystyle{ \text{d2}^{7,13}_{5} }[/math]
Special properties	superparticular, reduced
Tenney height (log2 nd)	12.9996
Weil height (log2 max(n, d))	13.0156
Wilson height (sopfr(nd))	33
Comma size	small
S-expression	S13 × S14
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The superparticular interval 91/90, the biome comma or superleap comma, is a small 13-limit comma of about 19 cents. It arises in several places in 13-limit just intonation, most notably as the difference between 13/12 and 15/14, between 13/9 and 7/5, between 7/6 and 15/13, and between 9/7 and 13/10 (and their octave complements, i.e. between 24/13 and 28/15, between 18/13 and 10/7, between 12/7 and 26/15, and between 14/9 and 20/13).

Temperaments

For temperaments eliminating this comma, see The Biosphere.

See also

• List of superparticular intervals