77/72

77/72, the undecimal secor, lies between the 3\31 secor of 31edo and the 10\103 secor of 103edo. It is 385/384 (4.5 cents) sharper than 16/15 and 540/539 (3.2 cents) flatter than 15/14. In 11-limit JI scales it often appears, being the interval between 12/11 and 7/6, 8/7 and 11/9, 9/7 and 11/8, and their inversions.

Interval information

Ratio	77/72
Factorization	2-3 × 3-2 × 7 × 11
Monzo	[-3 -2 0 1 1⟩
Size in cents	116.2338 ¢
Name	undecimal secor
Color name	1oz2, lozo 2nd
FJS name	[math]\displaystyle{ \text{m2}^{7,11} }[/math]
Special properties	reduced
Tenney norm (log2 nd)	12.4367
Weil norm (log2 max(n, d))	12.5336
Wilson norm (sopfr(nd))	30
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77/72 is extremely close to the mediant of 16/15 and 15/14, 31/29, differing only by 2233/2232 (0.7 cents).

Approximation

Tempering out 385/384 equates it with 16/15, tempering out 540/539 equates it with 15/14, and tempering out both makes it the marvel secor.

Tempering out 19712/19683 instead equates it with the apotome, with better accuracy than the former (2.5 cents).

See also

• 108/77 – its fifth complement
• Gallery of just intervals