5/2

Interval information

Ratio	5/2
Factorization	2-1 × 5
Monzo	[-1 0 1⟩
Size in cents	1586.314 ¢
Name	just major tenth
Color name	cy3, coyo 3rd
FJS name	[math]\displaystyle{ \text{M10}^{5} }[/math]
Tenney norm (log2 nd)	3.32193
Weil norm (log2 max(n, d))	4.64386
Wilson norm (sopfr(nd))	7
[sound info]
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5/2, the just major tenth, is the ratio between the 2nd and 5th harmonics; one octave above 5/4. It comes up in open voicings of various chords involving 5/4. For example, it is the bounding interval of 4:7:10 and 14:20:35, which may be used as the fundamental consonances of the 2.5.7 subgroup.

In 2026, CompactStar proposed the name sestertave for this interval in the context of using it an equivalence. This is derived by the same logic as "tritave", using a somewhat obscure Latin-based numerical prefix for 5/2, sester-, which literally means "half-three" (as in halfway to three if you start at two), found in words like "sestercentennial".

See also

• Ed5/2.