Meantone: Difference between revisions

Line 33:

'''Septimal meantone''' or '''7-limit meantone''' is a natural extension of meantone which also addresses septimal intervals including but not limited to [[7/4]], [[7/5]], and [[7/6]]. By extending the [[circle of fifths]], consonant septimal intervals start to appear. For example, 7/4 is represented by an augmented sixth (+10 fifths, C–A♯), and is notably present in the augmented sixth chord; it can also be seen as a diesis-flat minor seventh, as the diesis represents [[36/35]]~[[64/63]]. In septimal meantone, 7/5 is an augmented fourth, 7/6 is an augmented second, and [[9/7]] is a diminished fourth. Notably, septimal meantone equates the interval of a diminished fifth between the third and the seventh of a [[dominant seventh chord]] to [[10/7]], making it a [[9-odd-limit]] [[essentially tempered chord]]. Septimal meantone is best tuned close to [[31edo]].

'''Septimal meantone''' or '''7-limit meantone''' is a natural extension of meantone which also addresses septimal intervals including but not limited to [[7/4]], [[7/5]], and [[7/6]]. By extending the [[circle of fifths]], consonant septimal intervals start to appear. For example, 7/4 is represented by an augmented sixth (+10 fifths, C–A♯), and is notably present in the augmented sixth chord; it can also be seen as a diesis-flat minor seventh, as the diesis represents [[36/35]]~[[64/63]]. In septimal meantone, 7/5 is an augmented fourth, 7/6 is an augmented second, and [[9/7]] is a diminished fourth. Notably, septimal meantone equates the interval of a diminished fifth between the third and the seventh of a [[dominant seventh chord]] to [[10/7]], making it a [[9-odd-limit]] [[essentially tempered chord]]. Septimal meantone is best tuned close to [[31edo]] or [[Quarter-comma meantone|1/4-comma]].

~~See~~ [[huygens vs meanpop]] ~~for a comparison of undecimal~~ (11-~~limit~~) ~~extensions~~.

Extending meantone to the [[11-limit]] is not as simple. For one, there is the factorization of 81/80 as ([[121/120]])*([[243/242]]), and tempering both out leads to [[mohaha]] in the [[2.3.5.11 subgroup]], which splits the perfect fifth into two [[11/9]]~[[27/22]] neutral thirds. Adding back the septimal meantone mapping of 7 (+20 neutral thirds) gives [[migration]], but mohaha has an alternative mapping of [[7/4]] at the semi-diminished seventh (-13 neutral thirds), known as [[mohajira]]. Extensions to prime 11 generated by the perfect fifth are trickier. If 121/120 and 243/242 are not tempered out, then one of them must be mapped positively, and the other negatively. Since 121/120 is the difference between [[11/10]] and [[12/11]], it makes more sense to map it positively, and thus 243/242 negatively, leading 11/9 to be mapped wider than 27/22 and causing inconsistencies. Nonetheless, 31edo supports septimal meantone well while also having a neutral third, and there are two extensions generated by the fifth which map 11/9 to the neutral third. [[Undecimal meantone]] (also known as ''huygens'') maps 11/9 to +16 fifths (C–D𝄪) and 11/8 to +18 fifths (C–E𝄪), tempering out [[99/98]], [[176/175]], and [[441/440]]. Huygens works in the range from 31edo (696.8{{C}}) to 12edo (700{{C}}). The other extension is [[meanpop]], which maps 11/9 to -15 fifths (C–F𝄫) and 11/8 to -13 fifths (C–G𝄫), tempering out [[385/384]] and [[540/539]]. Tunings of meanpop range from 19edo (694.7{{C}}) to 31edo (696.8{{C}}).

=== Other septimal extensions ===

@@ Line 33: / Line 33: @@
 {{Wikipedia| Septimal meantone temperament }}
-'''Septimal meantone''' or '''7-limit meantone''' is a natural extension of meantone which also addresses septimal intervals including but not limited to [[7/4]], [[7/5]], and [[7/6]]. By extending the [[circle of fifths]], consonant septimal intervals start to appear. For example, 7/4 is represented by an augmented sixth (+10 fifths, C–A♯), and is notably present in the augmented sixth chord; it can also be seen as a diesis-flat minor seventh, as the diesis represents [[36/35]]~[[64/63]]. In septimal meantone, 7/5 is an augmented fourth, 7/6 is an augmented second, and [[9/7]] is a diminished fourth. Notably, septimal meantone equates the interval of a diminished fifth between the third and the seventh of a [[dominant seventh chord]] to [[10/7]], making it a [[9-odd-limit]] [[essentially tempered chord]]. Septimal meantone is best tuned close to [[31edo]].
+'''Septimal meantone''' or '''7-limit meantone''' is a natural extension of meantone which also addresses septimal intervals including but not limited to [[7/4]], [[7/5]], and [[7/6]]. By extending the [[circle of fifths]], consonant septimal intervals start to appear. For example, 7/4 is represented by an augmented sixth (+10 fifths, C–A♯), and is notably present in the augmented sixth chord; it can also be seen as a diesis-flat minor seventh, as the diesis represents [[36/35]]~[[64/63]]. In septimal meantone, 7/5 is an augmented fourth, 7/6 is an augmented second, and [[9/7]] is a diminished fourth. Notably, septimal meantone equates the interval of a diminished fifth between the third and the seventh of a [[dominant seventh chord]] to [[10/7]], making it a [[9-odd-limit]] [[essentially tempered chord]]. Septimal meantone is best tuned close to [[31edo]] or [[Quarter-comma meantone|1/4-comma]].
-See [[huygens vs meanpop]] for a comparison of undecimal (11-limit) extensions.
+Extending meantone to the [[11-limit]] is not as simple. For one, there is the factorization of 81/80 as ([[121/120]])*([[243/242]]), and tempering both out leads to [[mohaha]] in the [[2.3.5.11 subgroup]], which splits the perfect fifth into two [[11/9]]~[[27/22]] neutral thirds. Adding back the septimal meantone mapping of 7 (+20 neutral thirds) gives [[migration]], but mohaha has an alternative mapping of [[7/4]] at the semi-diminished seventh (-13 neutral thirds), known as [[mohajira]]. Extensions to prime 11 generated by the perfect fifth are trickier. If 121/120 and 243/242 are not tempered out, then one of them must be mapped positively, and the other negatively. Since 121/120 is the difference between [[11/10]] and [[12/11]], it makes more sense to map it positively, and thus 243/242 negatively, leading 11/9 to be mapped wider than 27/22 and causing inconsistencies. Nonetheless, 31edo supports septimal meantone well while also having a neutral third, and there are two extensions generated by the fifth which map 11/9 to the neutral third. [[Undecimal meantone]] (also known as ''huygens'') maps 11/9 to +16 fifths (C–D𝄪) and 11/8 to +18 fifths (C–E𝄪), tempering out [[99/98]], [[176/175]], and [[441/440]]. Huygens works in the range from 31edo (696.8{{C}}) to 12edo (700{{C}}). The other extension is [[meanpop]], which maps 11/9 to -15 fifths (C–F𝄫) and 11/8 to -13 fifths (C–G𝄫), tempering out [[385/384]] and [[540/539]]. Tunings of meanpop range from 19edo (694.7{{C}}) to 31edo (696.8{{C}}).
 === Other septimal extensions ===