50/49: Difference between revisions

Plumtree (talk | contribs)
m Normalising usage of Infobox Interval
+ etymology
 
(21 intermediate revisions by 10 users not shown)
Line 1: Line 1:
{{interwiki
{{Interwiki
| en = 50/49
| de = 50/49
| de = 50/49
| en = 50/49
| es =  
| es =  
| ja =  
| ja =  
}}
}}
{{Infobox Interval
{{Infobox Interval
| Name = jubilisma, septimal sixth-tone, tritonic diesis
| Name = small septimal diesis, small septimal sixth-tone, septimal tritonic diesis, jubilisma
| Color name = rryy-2, biruyo negative 2nd
| Color name = rryy-2, biruyo negative 2nd,<br>Biruyo comma
| Comma = yes
| Comma = yes
}}
}}
{{Wikipedia|Septimal third tone#Septimal sixth tone}}
{{Wikipedia|Septimal third tone #Septimal sixth tone}}


'''50/49''', the '''jubilisma''' (also '''septimal sixth-tone''' or '''tritonic diesis''') is a [[7-limit]] [[medium comma]]. It is the only [[superparticular]] [[comma]] aside from [[126/125]] which has a numerator which is neither square nor [[triangular number|triangular]], meaning it is not the difference between septimal superparticular rations with numerators differing by either one or two; instead, 50/49 = ([[10/7]])/([[7/5]]). [[Tempering out]] equates the two, leading to temperaments where the square root of two does service for both. Equal temperaments tempering out 50/49 include [[12edo]], [[22edo]], [[26edo]], [[38edo]], [[48edo]] and [[54edo]].
'''50/49''', the '''small septimal diesis''' (a.k.a. '''small septimal sixth-tone''' or '''septimal tritonic diesis'''), is a [[7-limit]] [[medium comma]]. It is the only [[superparticular]] [[comma]] in the 7-limit aside from [[126/125]] and [[4375/4374]] which has a numerator which is neither square nor [[triangular number|triangular]], meaning it is not the difference between septimal superparticular rations with numerators differing by either one or two; instead, {{nowrap| 50/49 = ([[10/7]])/([[7/5]]) }}.  
 
== Temperaments ==
[[Tempering out]] this comma equates the two septimal tritones (i.e. [[7/5]] and [[10/7]]) with each other, leading to temperaments where [[sqrt(2/1)]] approximates both. In the [[2.5.7 subgroup]], this is known as the jubilic temperament, and the comma is thus known as the '''jubilisma'''. In the full 7-limit, this comma further equates [[15/14]] and [[21/20]] and enables all the [[jubilismic chords]].
 
''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:
* ([[36/35]])/(50/49) = [[126/125]]
* ([[45/44]])/(50/49) = [[441/440]]
* ([[49/48]])/(50/49) = [[2401/2400]]
* (50/49)/([[55/54]]) = [[540/539]]
* (50/49)/([[56/55]]) = [[1375/1372]]
* (50/49)/([[64/63]]) = [[225/224]]
* (50/49)/([[65/64]]) = [[640/637]]
* (50/49)/([[66/65]]) = [[1625/1617]]
* (50/49)/([[78/77]]) = [[275/273]]
* (50/49)/([[81/80]]) = [[4000/3969]]
 
See [[Jubilismic family]] for the rank-3 family where it is tempered out, and [[Jubilismic clan]] for the rank-2 clan where it is tempered out.  
 
Equal temperaments tempering out 50/49 include [[12edo]], [[22edo]], [[26edo]], [[38edo]], [[48edo]], and [[54edo]].
 
== Approximations ==
{{Interval edo approximation|min_edo=12}}
 
== Etymology ==
The name ''jubilisma'' is likely a reference to the 50-year biblical jubilee cycle.  


== See also ==
== See also ==
* [[Jubilismic family]]
* [[Jubilismic clan]]
* [[List of superparticular intervals]]
* [[List of superparticular intervals]]
* [[49/48]] – the large septimal sixth-tone


[[Category:Jubilismic]]
[[Category:Jubilismic]]
 
[[Category:Commas referencing a famous use of a number]]
{{todo|clarify}} <!-- only superparticular comma... in the 7-limit only, maybe? -->