Systematic comma names explained: Difference between revisions
m Add see also |
→Johnston: explain how this works |
||
| (6 intermediate revisions by 2 users not shown) | |||
| Line 21: | Line 21: | ||
== Closing error == | == Closing error == | ||
=== 31-comma, 21-23-comma, etc. === | === 31-comma, 21-23-comma, 11-3/5 comma, etc. === | ||
These types of comma names show the [[closing error]] of a specific [[interval]] in a specific [[edo]]. | These types of comma names show the [[closing error]] of a specific [[interval]] in a specific [[edo]]. In general, an ''n''-''m''-comma, where ''n'' is a positive integer and ''m'' is a frequency ratio, is the difference between a stack of ''n'' instances of ''m'' and a number of octaves. ''m'' can be an integer, which means it is a harmonic. If the harmonic in question is the third harmonic (3/1), then it is left out of the comma name. | ||
An interval with a bigger denominator than numerator, like 3/5, indicates a negative interval. 3/5 for example is about -884 cents. A comma can still temper a stack of these. Just imagine it like a stack of 5/3's but going down instead of up. (In an edo, intervals that go down still wrap back around every octave, so this is possible.) | |||
For example, the ''31-5-comma'' is the difference between a stack of thirty-one 5/4's (5/4 is the octave-reduced harmonic 5) and 10 octaves, which is tempered out in 31edo. Meanwhile, the 31-comma is the difference between a stack of thirty-one 3/2's and eighteen octaves. As another example, the 11-3/5-comma is the difference between a stack of eleven 3/5's and minus eight octaves. | |||
These kinds of names can sometimes be mistaken for sagittal names (discussed later on this page) and vice versa, so be wary of that. | These kinds of names can sometimes be mistaken for sagittal names (discussed later on this page) and vice versa, so be wary of that. | ||
=== 87-fold starling comma, etc. === | === 87-fold starling comma, etc. === | ||
| Line 77: | Line 72: | ||
In this context, the term "chroma" implied an absolute 5-exponent of 1 within this system.{{clarify}} (But in wider xenharmonic usage, [[chroma]] is pretty vaguely defined and that does not necessarily apply). | In this context, the term "chroma" implied an absolute 5-exponent of 1 within this system.{{clarify}} (But in wider xenharmonic usage, [[chroma]] is pretty vaguely defined and that does not necessarily apply). | ||
{{todo|inline=1| | {{todo|inline=1|clarify|research|comment=explain how, exactly, the representative commas are chosen (the sagittal notation page doesn't explain it, and nor do any of its internal or external links)}} | ||
== Johnston == | == Johnston == | ||
=== 19th partial chroma, 29th partial chroma, etc. === | === 19th-partial chroma, 29th-partial chroma, etc. === | ||
These are commas named according to [[Ben Johnston's notation]]. | These are commas named according to [[Ben Johnston's notation]]. In general, the ''p''-th-partial chroma is the formal comma that translates a basic interval to an interval of the corresponding harmonic, or "partial". For example, the 19th-partial chroma is the difference between 6/5 and 19/16, so that using it on a 6/5 minor third converts it to 19/16. | ||
{{todo|inline=1| | {{todo|inline=1|complete section|research|comment=explain how, exactly, Ben Johnston's notation is used to name them (the Ben Johnston notation page doesn't explain it, nor do any of its internal or external links)}} | ||
== 35-cycle, 21-cycle, etc. == | == 35-cycle, 21-cycle, etc. == | ||
{{todo|inline=1| | {{todo|inline=1|complete section|research|comment=please explain this type of comma name}} | ||
== Prima, secunda, etc. == | == Prima, secunda, etc. == | ||
{{todo|inline=1| | {{todo|inline=1|complete section|research|comment=please explain this type of comma name}} | ||
== 34-jubilismic, 23 semitone, 19-minor mediant, etc. == | == 34-jubilismic, 23 semitone, 19-minor mediant, etc. == | ||
{{todo|inline=1| | {{todo|inline=1|complete section|research|comment=please explain this type of comma name; are these all the same type of name, or multiple different categories? Are they systematic?}} | ||
== See also == | == See also == | ||
* [[Comma-prefix names]] | |||
* [[Temperament naming]] | * [[Temperament naming]] | ||
* [[:Category:Commas by name]] | * [[:Category:Commas by name]] | ||
[[Category:Comma]][[Category:Terms]] | * [[Glossary]] | ||
* [[Acronyms]] | |||
[[Category:Comma]][[Category:Terms]][[Category:Interval naming]] | |||