Systematic comma names explained: Difference between revisions
→Closing error: rework this section to more concisely explain the rules |
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== 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. === | ||