# Why do I not hear polytonality with some keys?



## caters

Most of the time when I hear a polytonal piece, I can tell that it is polytonal. I find that that is the case with even a relative major relative minor pairing. But if it is polytonal, the 2 keys are both major, and they are a minor third apart, unless I hear a clash between the 3rd of 1 key and the root of another, I don't hear polytonality at all.

Like as long as I avoid an Eb/E clash, I can write something polytonal in C major and Eb major and I won't hear polytonality at all, but instead one single minor tonality, even if there is an E natural somewhere. I hear the parallel minor of the key that is lower within the octave, so in this case, C minor.

But why is it that, even if there are notes a semitone apart in the same piece and piece is polytonal, particularly between 2 major keys a minor third apart, I don't hear polytonality and instead hear a single minor key but if I play a piece with a relative major relative minor pairing, which are different modes of the same scale, I hear polytonality clearly?


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## millionrainbows

caters said:


> Most of the time when I hear a polytonal piece, I can tell that it is polytonal. I find that that is the case with even a relative major relative minor pairing. But if it is polytonal, the 2 keys are both major, and they are a minor third apart, unless I hear a clash between the 3rd of 1 key and the root of another, I don't hear polytonality at all.
> 
> Like as long as I avoid an Eb/E clash, I can write something polytonal in C major and Eb major and I won't hear polytonality at all, but instead one single minor tonality, even if there is an E natural somewhere. I hear the parallel minor of the key that is lower within the octave, so in this case, C minor.
> 
> But why is it that, even if there are notes a semitone apart in the same piece and piece is polytonal, particularly between 2 major keys a minor third apart, I don't hear polytonality and instead hear a single minor key but if I play a piece with a relative major relative minor pairing, which are different modes of the same scale, I hear polytonality clearly?


Two major keys a minor third apart, and you hear a single minor key? Unless you tell us what scales and what minor key you hear, your question is hard to answer.

Also, exactly what "polytonality" do you hear which results from the pairing of two relative maj/minor scales?

I need more specific info.


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## drmdjones

Interesting question, which I am sure I won't answer completely. 

Considering the unordered sets of pitch classes in the keys of C and Eb it is easy to see how, if the composer uses the pitches in a certain way (this is where the answer is to be found I believe), then one could hear Cm since the C melodic minor set contains all members of Eb and C except for E natural. This holds for all pairs of major keys a m3 apart.

To sound like Cm, however, the pitches would have to behave as they would in Cm. Specifically, the A natural and B natural would need to progress upward while the Ab and Bb would progress downward. 

Even the E natural could be contextualized as the leading tone to the subdominant in a V/iv to iv progression in Cm. Again it depends on the composer's use of this pitch. The composer would also need to avoid the non-functional clashes between E and Eb, as you mention, B and Bb, A and Ab. 

Most importantly, the pitch class C would need to be the focus of the passage. A tonality is not simply a set of pitches, it has a center, a tonic. 

Which leads to the other part of your question regarding C and Am (or any relative pair of keys). How they are used, rather than what they are, determines whether one or two tonalities will be heard. If you hear two keys in this case there are probably strong centers on both A and C.

Hope this helps.


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