Systematic comma names explained: Difference between revisions

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[[Comma]] names may be one of the more frustrating bits of xenharmonic theory to deal with. This is largely the result of smart and well-meaning theorists developing new standards to replace previous, flawed ones, only to end up with an [https://www.xkcd.com/927/ XKCD 927] situation.
This page aims to document some of the methods of systematically naming [[comma]]s, to help the reader make a bit more sense of some of the comma names out there.


This page aims to document some of the ways that commas are named, to help the reader make a bit more sense of some of the comma names out there.
This page does not cover ''common names'' for commas, it only covers names that were generated using some systematic process.


== Trienstonic, hendecatonic, etc. ==
== Trienstonic, hendecatonic, etc. ==
These are commas that generate a [[fractional-octave temperament]], or a family of them. For example hendecatonic means it generates an 11th-octave temperament, or a family of those.
Often, these are commas that generate a [[fractional-octave temperament]], but these type of names are not actually systematic. Usually these types of commas are named after the temperament, and not the other way around. To learn about some of these temperament names, visit [[Temperament naming]].


== Trientone, hexadecatone, etc. ==
== Trientone, hexadecatone, etc. ==
These are commas that are a fraction of a [[whole tone]] (~200 cents or ~[[9/8]]). For example, a trientone is about one third of a whole tone. A hexadecatone is about one sixteenth of a whole tone.
These are commas that are a fraction of a [[whole tone]] (~200 cents or ~[[9/8]]). For example, a trientone is about one third of a whole tone. A hexadecatone is about one sixteenth of a whole tone.
 
This method of naming is only semi-systematic, as there is still a level of subjectivity and vagueness involved, but it's still worth mentioning because it is used often.


== 31-comma, 21-23-comma, etc. ==
== 31-comma, 21-23-comma, etc. ==
These types of comma names are from [[sagittal notation]]. They 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]].


For example, the '''31-5-comma''' is the difference between a stack of 31 '''5/4'''s (5/4 is the octave reduces harmonic #5), and 10 octaves, which is tempered out in '''31edo'''.
For example, the '''31-5-comma''' is the difference between a stack of 31 '''5/4'''s (5/4 is the octave reduces harmonic #5), and 10 octaves, which is tempered out in '''31edo'''.
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== 5/7-kleisma, 35/11-kleisma, etc. ==
== 5/7-kleisma, 35/11-kleisma, etc. ==
These types of comma names come from an attempt to systematically name commas in around the year 2004. The commas were named according to the spreadsheet  
These types of comma names are derived from [[sagittal notation]]. Many of these were named using the spreadsheet  
[[File:CommaNamer.xls]].
[[File:CommaNamer.xls]], which was made in 2004.


The naming rules are a little difficult to work out, but "kleisma" definitely refers to the size of the interval - between 4.5 and 11.7 cents. The number in the name appears to have something to do with the prime factorization of the comma, but it is a bit difficult to reverse-engineer.
The naming rules for these kinds of commas can be found in the naming subsection of the sagittal notation page.


The full range of size classifications (rounded to 1 decimal place) was:
This type of name can occasionally get mixed up with the above type of name, for example "5-comma" is actually a sagittal name, even though it looks like the same type of thing as "31-comma". These clashes are unfortunate, but not fatal, as a look at the comma's page should reveal which system makes the most sense for interpeting its name.
* Less than 1.8 cents = schismina or atom
* 1.8 to 4.5 = schisma (''or skisma, skhisma'')
* 4.5 to 11.7 = kleisma (''or semicomma'')
* 11.7 to 35.2 = comma (''or dischisma, diaskhisma, chroma'')
* 35.2 to 45.1 = minor-diesis (''or small-diesis, 1/5-tone, chroma'')
* 45.1 to 56.8 = diesis (''or medium-diesis, 1/4-tone, chroma, enharmonic-diesis, enharmonic'')
* 56.8 to 68.6 = major-diesis (''or large-diesis, 1/3-tone'')
* 68.6 to 78.5 = chromatic-semitone (''or small-semitone'')
* 78.5 to 102.0 = limma (''or medium-semitone'')
* 102.0 to 111.9 = diatonic-semitone (''or large-semitone'')
* 111.9 to 115.5 = apotome
* 115.5 to 118.2 = schisma-plus-apotome
* 118.2 to 125.4 = kleisma-plus-apotome
* 125.4 to 148.9 = comma-plus-apotome
* 148.9 to 158.8 = minor-diesis-plus-apotome (''or neutral second'')
* 158.8 to 170.5 = diesis-plus-apotome
* 170.5 to 182.3 = major-diesis-plus-apotome
* 182.3 to 192.2 = chromatic-semitone-plus-apotome
* 192.2 to 215.6 = limma-plus-apotome
* 215.6 to 225.6 = diatonic-semitone-plus-apotome
* 225.6 to 229.2 = double-apotome
* Over 229.2 = outside the scope of this system


The term "chroma" implies an absolute 5-exponent of 1 within this system. (But in wider xenharmonic usage, [[chroma]] is pretty vaguely defined and that does not necessarily apply).
== 19th partial chroma, 29th partial chroma, etc. ==
 
These are commas named according to [[Ben Johnston's notation]]. That page should include information on the naming system.
The "plus-apotome" names are advised not to be used unless the interval is being considered first and foremost as a comma and not a scale degree.
 
{{todo|inline=1|expand|comment=reverse engineer the system and explain how it works}}


== 35-cycle, 21-cycle, etc. ==
== 35-cycle, 21-cycle, etc. ==
{{todo|inline=1|expand|comment=please explain this type of comma name}}
== 19th partial chroma, 29th partial chroma, etc. ==


{{todo|inline=1|expand|comment=please explain this type of comma name}}
{{todo|inline=1|expand|comment=please explain this type of comma name}}