27/25

Interval information

Ratio	27/25
Factorization	33 × 5-2
Monzo	[0 3 -2⟩
Size in cents	133.2376¢
Name	large limma
Color name	gg2, gugu 2nd
FJS name	[math]\displaystyle{ \text{m2}_{5,5} }[/math]
Special properties	reduced
Tenney height (log2 nd)	9.39874
Weil height (log2 max(n, d))	9.50978
Wilson height (sopfr(nd))	19
Comma size	large
S-expressions	S62 × S7, S3 / S5
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27/25, called the large limma or acute minor second, at 133.238 cents, has the remarkable property of almost exactly equaling a single step of 9edo, a step of which is 133 1/3 cents. Hence, nine large limmas fall just short of an octave by the ennealimma which is [1 -27 18⟩, a comma of less than a cent in size. If all of that were not enough, two large limmas are almost exactly a subminor third, since (7/6)/(27/25)² = 4375/4374. Turning from microtempering to exotempering, 27/25 can be tempered out, leading to the bug family of temperaments, rather than the ennealimmal temperament which tempering out both the ennealimma and 4375/4374, the ragisma, leads to.

Coincidentally, 27/25 is exactly three octaves below the ratio between 432hz and 50hz, common frequencies in tuning and AC electrical power respectively.

See also

• Gallery of just intervals
• Large comma