30/13

30/13 |1 1 1 0 0 -1>

1447.7410529609 cents

In 13-limit Just Intonation, 30/13 is an interseptimal interval measuring about 1447.7¢. It falls in an ambiguous zone between a narrow minor tenth such as 7/3 and a sharp perfect ninth such as 16/7. The descriptor "interseptimal" comes from Margo Schulter, and indicates its position between those two septimal (7-based) extremes. 30/13 appears between the 13th and 30th overtones of the harmonic series and appears in such chords as 8:10:13, a quasi-augmented triad. 30/13 also appears in the relatively-simple 10:13:15 triad, which consists of an interseptimal ultraminor tenth (30/13) and an interseptimal inframajor tenth (13/5) which stack to make a 6/1 perfect. It is well-approximated in 24edo, 29edo, 37edo, and of course, infinitely many other EDO systems.

See: Gallery of Just Intervals, List of root-3rd-P5 triads in JI