Talk:Inversion (music)

Just wanted to note that I'm still not very comfortable with the idea that inverted octaves become unisons and vice versa (see talk:octave). It's probably just me (though it is notable that most theory textbooks (the ones I've looked at, anyway) tell us what happens when you invert seconds, thirds, fourths, fifths, sixths and sevenths, but not unisons or octaves). --Camembert

Hi Camembert--Maybe it would help resolve the issue by asking what is the purpose of referring to inverted intervals. For all of the other cases of inversion ((1) inverted melody, (2) inverting two parts in counterpoint, (3) inversions of a chord), I can think of cases where the terminology is useful in describing a work of music ((1) "following the aria, the fugal theme reappears inverted" (Beeth. op. 110); (2) "the two themes now appear inverted, with the main theme in the lower part" (Bach 2 pt. inv. E); (3) "the second inversion of the tonic chord is used to introduce a cadenza" (any Classical concerto)). But where do commentators talk about inverted intervals when discussing actual pieces? I don't know the answer, but it seems to me that if commentators do make use of "seventh = inverted second", but never make use of "octave = inverted unison", then that ought to settle the issue in your favor (since our goal is to be useful to readers). Just a thought. Opus33 21:35, 23 Dec 2003 (UTC)

Well, I can't come up with any examples of commentators talking about inverted intervals in practice, but I suppose the most common context in which one would want to talk about them would be when melodies switch places in a contrapuntal texture (your number (2) above) - if you have melody A in the treble and melody B in the bass, and then later you put melody B in the treble and melody A in the bass, then all the intervals between voices in that second version are inverted. In that case it's not possible to generalise about what will happen to octaves and unisons - notes that were previously an octave (or more) apart may remain an octave (or more) apart, or they may become unisons, and vice versa - it all depends how many octaves apart the two voices are. The whole question is irrelevant, really, because the number of octaves apart the voices are is not interesting - only the pitch classes (that is, whether you've got a D or an F sharp or whatever) are. One might also want to speak of inverted intervals in the context of twelve-tone pieces, when again octaves are neither here nor there. So the question of what unisons and octaves become when inverted is really irrelevant, because if you had a C on the top and a C on the bottom before inversion, you do after inversion as well. That's my view of it, anyway. --Camembert

Beginning music theory students are taught about how to invert intervals. Why? Good question.Hyacinth 04:12, 25 Dec 2003 (UTC)

PS. In the last ten minutes I managed to go from complete boredom with this discussion back to complete interest. Anyways, the article is settled, and we could stop talking about this.Hyacinth