28/27: Difference between revisions

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Although called a ''chroma'' for its proximity (and conflation in systems like septimal [[meantone]]) with the classic chroma [[25/24]], 28/27 is a ''diatonic semitone'' in both [[Helmholtz-Ellis notation]] and [[Functional Just System]] because it is [[64/63]] smaller than the Pythagorean minor second [[256/243]]. Hence, it may be described as the '''septimal minor second''' or '''subminor second''' if treated as an interval in its own right. This is analogous to the septimal major second [[8/7]], which has the same relationship with [[9/8]], and such classification suggests the function of a strong leading tone added to the traditional harmony.  
Although called a ''chroma'' for its proximity (and conflation in systems like septimal [[meantone]]) with the classic chroma [[25/24]], 28/27 is a ''diatonic semitone'' in both [[Helmholtz-Ellis notation]] and [[Functional Just System]] because it is [[64/63]] smaller than the Pythagorean minor second [[256/243]]. Hence, it may be described as the '''septimal minor second''' or '''subminor second''' if treated as an interval in its own right. This is analogous to the septimal major second [[8/7]], which has the same relationship with [[9/8]], and such classification suggests the function of a strong leading tone added to the traditional harmony.  
It is very accurately approximated by [[19edo]] (1\19).


== See also ==
== See also ==

Revision as of 09:59, 15 October 2020

Interval information
Ratio 28/27
Factorization 22 × 3-3 × 7
Monzo [2 -3 0 1
Size in cents 62.9609¢
Names small septimal chroma,
septimal third-tone,
subminor second,
septimal minor second
Color name z2, zo 2nd
FJS name [math]\displaystyle{ \text{m2}^{7} }[/math]
Special properties superparticular,
reduced
Tenney norm (log2 nd) 9.56224
Weil norm (log2 max(n, d)) 9.61471
Wilson norm (sopfr(nd)) 20

[sound info]
Open this interval in xen-calc

The superparticular interval 28/27 (also small septimal chroma or septimal third-tone) has the seventh triangular number as a numerator and is the difference between 15/14 and 10/9, 9/8 and 7/6, 9/7 and 4/3, 3/2 and 14/9, 12/7 and 16/9, and 9/5 and 28/15.

Although called a chroma for its proximity (and conflation in systems like septimal meantone) with the classic chroma 25/24, 28/27 is a diatonic semitone in both Helmholtz-Ellis notation and Functional Just System because it is 64/63 smaller than the Pythagorean minor second 256/243. Hence, it may be described as the septimal minor second or subminor second if treated as an interval in its own right. This is analogous to the septimal major second 8/7, which has the same relationship with 9/8, and such classification suggests the function of a strong leading tone added to the traditional harmony.

It is very accurately approximated by 19edo (1\19).

See also