81/70: Difference between revisions

From Xenharmonic Wiki
Jump to navigation Jump to search
Xenwolf (talk | contribs)
m See also: added link to 5th compl.
Fredg999 category edits (talk | contribs)
 
(13 intermediate revisions by 6 users not shown)
Line 1: Line 1:
{{Infobox Interval
{{Infobox Interval
| Ratio = 81/70
| Name = septimal ultramajor second
| Monzo = -1 4 -1 -1
| Cents = 252.6804
| Name = septimal semiaugmented second, <br>septimal ultramajor second
| Color name = rg2, rugu 2nd
| Color name = rg2, rugu 2nd
| Sound =  
| Sound = Ji-81-70-csound-foscil-220hz.mp3
}}
}}
'''81/70''', the '''septimal ultramajor second''' is a [[7-limit]] [[interseptimal]] ratio of about 253 [[cent]]s. It is sharp of a major second [[9/8]] by a septimal quartertone [[36/35]], sharp of a supermajor second [[8/7]] by a syntonic comma [[81/80]], and flat of a subminor third [[7/6]] by a sensamagic comma [[245/243]].


'''81/70''', the '''septimal semiaugmented second''' or '''septimal ultramajor second''' is a [[7-limit]] [[interseptimal]] ratio of about 253 cents. It is sharp of a subminor third [[7/6]] by a sensamagic comma [[245/243]], and sharp of a major second [[16/9]] by a septimal quartertone [[36/35]].  
Notice it is also flat of the just minor third [[6/5]] by a subminor second [[28/27]]. For this fact it is useful in the [[sensamagic dominant chord]] where it functions as a dissonance yet to be resolved up to the minor third. The [[Canou family|canou temperament]] targets this progression and uses it as one of the generators.  


It is also sharp of a minor third [[6/5]] by a subminor second [[28/27]]. For this fact it is useful in the [[Canovian chord]] and provides the function of a voice leading up to the minor third.
== Approximation ==
 
It is near-perfectly approximated by [[19edo]] (4\19), with an error of 0.05 cents, and hence equally well done by the [[enneadecal]] temperament.
The interval is so perfectly approximated by [[19edo|19-edo]], with an error of 0.05 cents. There are a number of edos that do this equally well, [[171edo|171-edo]] to name one. The first edo that does this better than 19-edo with patent val is [[660edo|660-edo]].  


== See also ==
== See also ==
* [[140/81]] – its [[octave complement]]
* [[140/81]] – its [[octave complement]]
* [[35/27]] – its [[fifth complement]]
* [[35/27]] – its [[fifth complement]]
* [[Gallery of just intervals]]
* [[Gallery of just intervals]]


[[Category:7-limit]]
[[Category:Interval]]
[[Category:Ratio]]
[[Category:Second]]
[[Category:Second]]
[[Category:Whole tone]]
[[Category:Supermajor second]]
[[Category:Interseptimal]]
[[Category:Interseptimal intervals]]
[[Category:Semifourth]]

Latest revision as of 03:27, 28 April 2023

Interval information
Ratio 81/70
Factorization 2-1 × 34 × 5-1 × 7-1
Monzo [-1 4 -1 -1
Size in cents 252.6804¢
Name septimal ultramajor second
Color name rg2, rugu 2nd
FJS name [math]\displaystyle{ \text{M2}_{5,7} }[/math]
Special properties reduced
Tenney norm (log2 nd) 12.4691
Weil norm (log2 max(n, d)) 12.6797
Wilson norm (sopfr(nd)) 26

[sound info]
Open this interval in xen-calc

81/70, the septimal ultramajor second is a 7-limit interseptimal ratio of about 253 cents. It is sharp of a major second 9/8 by a septimal quartertone 36/35, sharp of a supermajor second 8/7 by a syntonic comma 81/80, and flat of a subminor third 7/6 by a sensamagic comma 245/243.

Notice it is also flat of the just minor third 6/5 by a subminor second 28/27. For this fact it is useful in the sensamagic dominant chord where it functions as a dissonance yet to be resolved up to the minor third. The canou temperament targets this progression and uses it as one of the generators.

Approximation

It is near-perfectly approximated by 19edo (4\19), with an error of 0.05 cents, and hence equally well done by the enneadecal temperament.

See also