245/243: Difference between revisions
Created page with "{{Infobox Interval | Ratio = 245/243 | Monzo = 0 -5 1 2 | Cents = 14.19052 | Name = Sensamagic comma | Color name = zzy2, zozoyo 2nd | Sound = }} '''245/243''', the '''sensa..." |
No edit summary |
||
| (25 intermediate revisions by 11 users not shown) | |||
| Line 1: | Line 1: | ||
{{interwiki | |||
| de = 245/243 | |||
| en = 245/243 | |||
}} | |||
{{Infobox Interval | {{Infobox Interval | ||
| Name = sensamagic comma | |||
| Color name = zzy2, zozoyo 2nd,<br>Zozoyo comma | |||
| Comma = yes | |||
| Name = | |||
| Color name = zzy2, zozoyo 2nd | |||
| | |||
}} | }} | ||
'''245/243''', the '''sensamagic comma''', is a [[small comma|small]] [[7-limit]] [[comma]] measuring 14.2 [[cent]]s. It is the amount by which two septimal major thirds ([[9/7]]) fall short of a classic major sixth ([[5/3]]), or the difference between [[28/27]] and [[36/35]]. | |||
== Temperaments == | |||
[[Tempering out]] this comma alone in the 7-limit leads to the [[sensamagic]] temperament, where 5/3 is split into two equal parts, each representing 9/7~[[35/27]], and may be extended to represent higher-limit ratios like [[13/10]], [[22/17]], etc. It enables [[sensamagic chords]]. | |||
Tempering it out in the [[3.5.7 subgroup]] leads to the non-octave [[BPS]] temperament, which features a [[4L 5s (3/1-equivalent)|lambda scale]] as is found in [[13edt]], the [[Bohlen–Pierce scale]]. | |||
See [[Sensamagic family]] for the rank-3 temperament family where it is tempered out. See [[Sensamagic clan]] for the rank-2 clan where it is tempered out. | |||
== Etymology == | |||
This comma was first named as ''octarod'' by [[Gene Ward Smith]] in 2005 as a contraction of ''[[octacot]]'' and ''[[rodan]]''<ref>[https://yahootuninggroupsultimatebackup.github.io/tuning-math/topicId_12900.html Yahoo! Tuning Group | ''Seven limit comma names from pairs of temperament names'']</ref>, and was renamed to ''sensamagic'' in 2010 as a concatenation of [[sensi]] and [[magic]]<ref>[https://yahootuninggroupsultimatebackup.github.io/tuning/topicId_88759.html Yahoo! Tuning Group | ''Some unnamed 7-limit temperaments'']</ref>. | |||
<blockquote> | |||
Here's a thought: 245/243 tells us that two 9/7['s] make up a 5/3. Hence, the temperaments which most exploit this and for which the comma is most characteristic are the ones where 9/7 has a low complexity. And this means sensi (complexity 1) and magic (complexity 2). So my proposal "sensamagic" is the way to go by this reasoning, which strikes me as pretty strong. | |||
</blockquote> | |||
—Gene Ward Smith | |||
In 2025, [[Tristan Bay]] proposed ''lambda comma'' to reflect the fact that [[edt]]s which temper this comma out contain the aforementioned lambda scale (and is accurately tuned in the corresponding temperament, relative to the size of the edt). | |||
== See also == | == See also == | ||
* [[Gallery of just intervals]] | |||
== Notes == | |||
<references /> | |||
[[Category:Sensamagic]] | [[Category:Sensamagic]] | ||
[[Category:Bohlen–Pierce]] | |||
[[Category:Commas named by combining multiple temperament names]] | |||