49/48: Difference between revisions
distinctly consistent redirects to consistency so arguably that is the error that needs to be fixed as the consistency page is where it's defined but it doesnt have its own section Tag: Undo |
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{{Infobox Interval | {{Infobox Interval | ||
| Name = large septimal diesis, slendro diesis | | Name = large septimal diesis, large septimal sixth-tone, slendro diesis, semaphore comma, semaphoresma | ||
| Color name = zz2, zozo 2nd,<br> | | Color name = zz2, zozo 2nd,<br>zzM, zozoma | ||
| Sound = Ji-49-48-csound-foscil-220hz.mp3 | | Sound = Ji-49-48-csound-foscil-220hz.mp3 | ||
| Comma = yes | | Comma = yes | ||
}} | }} | ||
{{Wikipedia|Septimal diesis}} | {{Wikipedia|Septimal diesis}} | ||
'''49/48''', the '''large septimal diesis''' (or '''slendro diesis'''), is a [[superparticular]] ratio spanning the small distance between a subminor third ([[7/6]]) and a supermajor second ([[8/7]]) or between the supermajor sixth ([[12/7]]) and the harmonic seventh ([[7/4]]). Measuring about 35.7{{cent}}, it is a [[medium comma]]; however, in classical Western music, this interval is not known as a [[comma]] as it is not tempered out in [[12edo]]. | '''49/48''', the '''large septimal diesis''' (a.k.a. '''large septimal sixth-tone''' or '''slendro diesis'''), is a [[7-limit]] [[superparticular]] ratio spanning the small distance between a subminor third ([[7/6]]) and a supermajor second ([[8/7]]) or between the supermajor sixth ([[12/7]]) and the harmonic seventh ([[7/4]]). Measuring about 35.7{{cent}}, it is a [[medium comma]]; however, in classical Western music, this interval is not known as a [[comma]] as it is not tempered out in [[12edo|12tet]]. | ||
49/48 is [[tempered out]] in [[15edo]] and [[19edo]], where | This interval has a function similar to [[25/24]] in that it separates the [[7/6]] and [[8/7]] intervals in a [[6:7:8]] triad, similarly to how [[25/24]] separates [[5/4]] and [[6/5]] in a [[4:5:6]] triad. The 6:7:8 triad consists of odd [[harmonic]]s [[1/1|1]], [[3/1|3]], and [[7/1|7]] [[octave reduced]] to span the [[4/3|perfect fourth]], while the 4:5:6 triad consists of odd harmonics 1, 3, and 5 octave reduced to span the [[3/2|perfect fifth]]. In that regard, tempering out 49/48 can be considered a form of [[exotemperament|exotempering]] that neutralizes the 6:7:8 chord and equates it with its inverse [[21:24:28|1/(8:7:6)]], just like how [[dicot]], which tempers out 25/24, neutralizes the 4:5:6 chord and equates it with its inverse [[10:12:15|1/(6:5:4)]]. | ||
== Temperaments == | |||
49/48 is [[tempered out]] in [[15edo]] and [[19edo]], where 7/6 and 8/7 are equated, and the fourth is split in a perfect half. 3/1 is also split into two [[7/4]]~[[12/7]]'s. In the 2.3.7 [[subgroup]], this is known as the [[semaphore]] temperament, and the comma is thus known as the '''semaphore comma''' or '''semaphoresma'''. | |||
''It cannot be tempered out if all of the consonances of the 7-odd-limit are distinct'', but it ''can'' be equated with other commas; for example: | |||
* (49/48)/([[81/80]]) = [[245/243]] | |||
* (49/48)/([[64/63]]) = [[1029/1024]] | |||
* (49/48)/([[3125/3072]]) = [[3136/3125]] | |||
* (49/48)/([[50/49]]) = [[2401/2400]] | |||
* ([[128/125]])/(49/48) = [[6144/6125]] | |||
* ([[36/35]])/(49/48) = [[1728/1715]] | |||
See [[Semaphoresmic family]] for the rank-3 family where it is tempered out. See [[Semaphoresmic clan]] for the rank-2 clan where it is tempered out. | |||
== Approximations == | |||
{{interval edo approximation|min_edo=5}} | |||
== See also == | == See also == | ||
* [[Medium comma]] | * [[Medium comma]] | ||
* [[List of superparticular intervals]] | * [[List of superparticular intervals]] | ||
* [[Gallery of just intervals]] | * [[Gallery of just intervals]] | ||
[[Category: | [[Category:Semaphore]] | ||
[[Category: | [[Category:Semaphoresmic]] | ||
[[Category:Commas named for how they divide the fourth]] | |||
[[Category:Commas named after musical traditions]] | |||