12/7: Difference between revisions

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less obscure chord example; 4:5:7:9:12 is more often written as 4:5:6:7:9
 
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{{Wikipedia| Septimal major sixth }}
{{Wikipedia| Septimal major sixth }}


In [[7-limit]] [[just intonation]], '''12/7''' is the '''septimal (super)major sixth''' of about 933.1¢. It represents the interval between the 12th and 7th harmonics and appears in chords such as 4:5:7:9:12. It differs from the 5-limit major sixth of [[5/3]] by [[36/35]] – the septimal quartertone – a [[superparticular]] interval of about 48.8¢. It differs from the Pythagorean major sixth of [[27/16]] by [[64/63]] – Archytas' comma – about 27.3¢. And finally, it differs from the harmonic seventh of [[7/4]] by [[49/48]] – the large septimal diesis or slendro diesis – about 35.7¢. 12/7 is the inversion of the septimal subminor third of [[7/6]].
In [[7-limit]] [[just intonation]], '''12/7''' is the '''septimal (super)major sixth''' of about 933.1¢. It represents the interval between the 12th and 7th harmonics and appears in chords such as [[70:84:105:120|1/(12:10:8:7)]]. It differs from the 5-limit major sixth of [[5/3]] by [[36/35]] – the septimal quartertone – a [[superparticular]] interval of about 48.8¢. It differs from the Pythagorean major sixth of [[27/16]] by [[64/63]] – Archytas' comma – about 27.3¢. And finally, it differs from the harmonic seventh of [[7/4]] by [[49/48]] – the large septimal diesis or slendro diesis – about 35.7¢. 12/7 is the inversion of the septimal subminor third of [[7/6]].
== Approximation ==
{{Interval edo approximation|12/7}}


== See also ==  
== See also ==  

Latest revision as of 08:39, 25 December 2025

Interval information
Ratio 12/7
Factorization 22 × 3 × 7-1
Monzo [2 1 0 -1
Size in cents 933.1291¢
Names supermajor sixth,
septimal major sixth
Color name r6, ru 6th
FJS name [math]\displaystyle{ \text{M6}_{7} }[/math]
Special properties reduced
Tenney norm (log2 nd) 6.39232
Weil norm (log2 max(n, d)) 7.16993
Wilson norm (sopfr(nd)) 14

[sound info]
Open this interval in xen-calc
English Wikipedia has an article on:

In 7-limit just intonation, 12/7 is the septimal (super)major sixth of about 933.1¢. It represents the interval between the 12th and 7th harmonics and appears in chords such as 1/(12:10:8:7). It differs from the 5-limit major sixth of 5/3 by 36/35 – the septimal quartertone – a superparticular interval of about 48.8¢. It differs from the Pythagorean major sixth of 27/16 by 64/63 – Archytas' comma – about 27.3¢. And finally, it differs from the harmonic seventh of 7/4 by 49/48 – the large septimal diesis or slendro diesis – about 35.7¢. 12/7 is the inversion of the septimal subminor third of 7/6.

Approximation

Edo approximations for 12/7 (933.13 ¢)
≤ 80edo, relative error ≤ 10%
Edo Step size Cents (¢) Absolute error (¢) Relative error (%)
9 7\9 933.33 +0.20 +0.15
18 14\18 933.33 +0.20 +0.31
27 21\27 933.33 +0.20 +0.46
36 28\36 933.33 +0.20 +0.61
45 35\45 933.33 +0.20 +0.77
54 42\54 933.33 +0.20 +0.92
63 49\63 933.33 +0.20 +1.07
67 52\67 931.34 -1.79 -9.97
72 56\72 933.33 +0.20 +1.23
76 59\76 931.58 -1.55 -9.82

See also