28/27: Difference between revisions

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), and hence the enneadecal temperament.

@@ Line 12: / Line 12: @@
 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.
+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).
+It is very accurately approximated by [[19edo]] (1\19), and hence the [[enneadecal]] temperament.
 == See also ==

28/27: Difference between revisions

Revision as of 05:27, 5 January 2021

See also

Navigation menu

Search