28/27: Difference between revisions

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{{Infobox Interval

| ~~Icon~~ =

| Name = septimal third-tone, small septimal chroma, subminor second, septimal minor second, septimal subminor second, trienstonic comma

~~| Ratio = 28/27~~

~~| Monzo = 2~~ -~~3 0 1~~

~~| Cents = 62.9609~~

~~| Name =~~ septimal chroma, septimal ~~third-tone~~

| Color name = z2, zo 2nd

| Sound = jid_28_27_pluck_adu_dr220.mp3

| Comma = yes

}}

The [[superparticular]] interval '''28/27''' ~~(also '''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 [[28/25]].

The [[superparticular]] interval '''28/27''', '''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]].

== Terminology ==

28/27 is traditionally called the '''small septimal chroma''', perhaps for its proximity (and conflation in systems like [[septimal meantone]]) with the classic chroma, [[25/24]]. However, it is a ''[[diatonic semitone]]'' in just intonation notation systems such as [[Sagittal notation]], [[Helmholtz–Ellis notation]], and the [[Functional Just System]], viewed as the [[256/243|Pythagorean limma (256/243)]] altered by the [[64/63|septimal comma (64/63)]]. Hence, it may be described as the '''septimal minor second''' or '''septimal 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.

== Approximation ==

This interval is very accurately approximated by [[19edo]] (1\19), and hence the [[enneadecal]] temperament.

== Temperaments ==

If treated as a [[comma]] to be tempered out, 28/27 may be called the '''trienstonic comma''', which leads to the '''trienstonic temperaments'''. See [[Trienstonic clan]] for the rank-2 clan of temperaments where it is tempered out.

== Notation ==

=== Sagittal notation ===

In the [[Sagittal]] system, this comma (possibly tempered) is represented (in a secondary role) by the sagittal {{sagittal| (|\ }} and is called the '''7 large diesis''', or '''7L''' for short, because the simplest interval it notates is 7/1 (equivalently, 7/4), as for example in C–A{{nbhsp}}{{sagittal | (|\ }}. The primary role of {{sagittal| (|\ }} is [[8505/8192 #Sagittal notation|8505/8192]] (35L). The downward version is called '''1/7L''' or '''7L down''' and is represented (in a secondary role) by {{sagittal| (!/ }}.

== See also ==

* [[Gallery of ~~Just Intervals~~]]

* [[27/14]] – its [[octave complement]]

* [~~https:~~//~~en.wikipedia.org/wiki/Septimal_third_tone Septimal third tone - Wikipedia~~]

* [[81/56]] – its [[fifth complement]]

* [[9/7]] – its [[fourth complement]]

* [[List of superparticular intervals]]

* [[Gallery of just intervals]]

* [[Trienstonisma]], the difference by which a stack of five 28/27's falls short of [[6/5]]

[[Category:~~7-limit~~]]

[[Category:Second]]

[[Category:~~Interval]]~~

[[Category:Semitone]]

~~[[Category:Superparticular~~]]

[[Category:Third tone]]

[[Category:Chroma]]

[[Category:Trienstonic]]

[[Category:Commas named for the intervals they stack]]

@@ Line 1: / Line 1: @@
 {{Infobox Interval
-| Icon =
+| Name = septimal third-tone, small septimal chroma, subminor second, septimal minor second, septimal subminor second, trienstonic comma
-| Ratio = 28/27
-| Monzo = 2 -3 0 1
-| Cents = 62.9609
-| Name = septimal chroma, septimal third-tone
 | Color name = z2, zo 2nd
 | Sound = jid_28_27_pluck_adu_dr220.mp3
+| Comma = yes
 }}
+{{Wikipedia| Septimal third tone }}
-The [[superparticular]] interval '''28/27''' (also '''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 [[28/25]].
+The [[superparticular]] interval '''28/27''', '''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]].
+== Terminology ==
+/27 is traditionally called the '''small septimal chroma''', perhaps for its proximity (and conflation in systems like [[septimal meantone]]) with the classic chroma, [[25/24]]. However, it is a ''[[diatonic semitone]]'' in just intonation notation systems such as [[Sagittal notation]], [[Helmholtz–Ellis notation]], and the [[Functional Just System]], viewed as the [[256/243|Pythagorean limma (256/243)]] altered by the [[64/63|septimal comma (64/63)]]. Hence, it may be described as the '''septimal minor second''' or '''septimal 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.
+== Approximation ==
+This interval is very accurately approximated by [[19edo]] (1\19), and hence the [[enneadecal]] temperament.
+== Temperaments ==
+If treated as a [[comma]] to be tempered out, 28/27 may be called the '''trienstonic comma''', which leads to the '''trienstonic temperaments'''. See [[Trienstonic clan]] for the rank-2 clan of temperaments where it is tempered out.
+== Notation ==
+=== Sagittal notation ===
+In the [[Sagittal]] system, this comma (possibly tempered) is represented (in a secondary role) by the sagittal {{sagittal| (|\ }} and is called the '''7 large diesis''', or '''7L''' for short, because the simplest interval it notates is 7/1 (equivalently, 7/4), as for example in C–A{{nbhsp}}{{sagittal | (|\ }}. The primary role of {{sagittal| (|\ }} is [[8505/8192 #Sagittal notation|8505/8192]] (35L). The downward version is called '''1/7L''' or '''7L down''' and is represented (in a secondary role) by {{sagittal| (!/ }}.
 == See also ==
-* [[Gallery of Just Intervals]]
+* [[27/14]] – its [[octave complement]]
-* [https://en.wikipedia.org/wiki/Septimal_third_tone Septimal third tone &#45; Wikipedia]
+* [[81/56]] – its [[fifth complement]]
+* [[9/7]] – its [[fourth complement]]
+* [[List of superparticular intervals]]
+* [[Gallery of just intervals]]
+* [[Trienstonisma]], the difference by which a stack of five 28/27's falls short of [[6/5]]
-[[Category:7-limit]]
+[[Category:Second]]
-[[Category:Interval]]
+[[Category:Semitone]]
-[[Category:Superparticular]]
 [[Category:Third tone]]
 [[Category:Chroma]]
+[[Category:Trienstonic]]
+[[Category:Commas named for the intervals they stack]]
+{{Todo| improve synopsis }}