Otonality and utonality: Difference between revisions

Dummy index (talk | contribs)
Scales: fix
+ an actual intro, more to come
Line 1: Line 1:
{{interwiki
{{Interwiki
| en = Otonality and utonality
| de =  
| de =  
| en = Otonality and utonality
| es =  
| es =  
| ja = OtonalityとUtonality
| ja = OtonalityとUtonality
}}
}}
{{Wikipedia|Otonality and Utonality}}
{{Wikipedia|Otonality and Utonality}}
'''Otonality''' and '''utonality''' are properties of [[chord]]s that describe if it is simpler to treat them as part of the [[harmonic series]] or [[subharmonic series]].
== Introduction ==
== Introduction ==
Given a JI chord, how can we decide whether it is otonal or utonal? This might seem obvious at first, but it's actually surprisingly subtle. For example, the chord 10:12:15 is a 5-limit utonality (1/6:1/5:1/4), but it's also a 15-limit otonality, consisting of the 10th, 12th, and 15th harmonics of a fundamental. One reasonable definition is to say that a chord is otonal if its largest odd number is smaller than the largest odd number of its inverse, and utonal if the inverse has a smaller largest-odd-number. In other words, if inverting a chord increases its odd limit, it's otonal, and if it reduces it, it's utonal. That way 4:5:6 is otonal because it's simpler than its inverse, 10:12:15, and 10:12:15 is utonal because it is more simply expressed as 1/6:1/5:1/4. Because we're using odd limit and not integer limit, this definition is independent of the chord's voicing. Thus 4:5:6 is otonal even if voiced 3:4:5 or 2:3:5.
Given a JI chord, how can we decide whether it is otonal or utonal? This might seem obvious at first, but it's actually surprisingly subtle. For example, the chord 10:12:15 is a 5-limit utonality (1/6:1/5:1/4), but it's also a 15-limit otonality, consisting of the 10th, 12th, and 15th harmonics of a fundamental. One reasonable definition is to say that a chord is otonal if its largest odd number is smaller than the largest odd number of its inverse, and utonal if the inverse has a smaller largest-odd-number. In other words, if inverting a chord increases its odd limit, it's otonal, and if it reduces it, it's utonal. That way 4:5:6 is otonal because it's simpler than its inverse, 10:12:15, and 10:12:15 is utonal because it is more simply expressed as 1/6:1/5:1/4. Because we're using odd limit and not integer limit, this definition is independent of the chord's voicing. Thus 4:5:6 is otonal even if voiced 3:4:5 or 2:3:5.
Line 67: Line 70:


[[Category:Otonality and utonality| ]] <!-- main article -->
[[Category:Otonality and utonality| ]] <!-- main article -->
{{Todo|improve synopsis}}