CHORDS: Extended vs Poly

[SkinnyDevil]

So I was having this discussion. Theh topic of polychords comes up. I answer by saying polychords are basically 2 triads played at the same time. So one guy says it's just a fancy name for an extended chord. I say, no - while some people think of certain extensions that way (and they certainly are, of course), a polychord, proper, is a combination of 2 chords not from the same key.

In the key of C, for example:

Extended: Am plus G major = Am11 (A C E G B D)
Polychord: Am plus G minor = Am-G (not Am/G, of course)

He says, no, one can view Am11 as a polychord made of two triads. I respond that it may help him think of it that way, but technically speakign it's still not a polychord. Polychords, as I said, are chords from 2 different keys played together. He says no, but even if it was yes, then what about funky chords with lots of sharps of flats or augs or dims? What about an Am13b5, buddy? I say good point, but one would have to look at the context of the song. If the song just has a lot of cool chromatic lines, then it's an extended chord. If, on the other hand, the song has independent lines from different keys (or heavily implies bitonality or polytonality) then it's a polychord.

He says I'm full of **** and being an elitist. I said I have no problem with viewing a complex chord as poly AS A TOOL to help get a grip on it, but it doesn;t mean it IS a polychord. Elitism has nothing to do with it. You can flap your arms, but it doesn't make you a bird...even if you have a boarding pass.

Perhaps someone can weigh in and either correct me if I'm wrong or give me some way to help him understand the difference.

Thanx in advance.

[Jed]

Well beyond my level, but I searched wiki for some background. The listing under poly-chord was just a stub but linked to the use of poly-chords as a bi- or poly-tonal technique under polytonality.

http://en.wikipedia.org/wiki/Polytonality

I'm pretty limited harmonically so I only use the term & effect of triads over other triads / 7th chords as a way to extend basic chords. But the thought of actually playing in a different key and making it work is fascinating. Any one have any examples of the technique as an mp3?

cheers,

[Poparad]

It all depends on context. A C E G B D can be both Am11 and Am over G major, depending on the situation. If it's found in a situation where there are lots of 7th chords and extended chords, then it's probably not a polychord. If it's found in a situation with lots of other (more obvious) polychords, then it's probably a polychord.

The two triads don't need to be from different keys to be a polychord; D major of C major is a common polychord, but they're both found in the key of G.

Polychords can also be used as an effective way to voice extended chords to achieve the unique sound of the two distinct triads. D major over C major is commonly used to create a Cmaj13(#11) chord (missing a 7th, of course) in an song that otherwise uses 7th chords and other extended chords.

[JonR]

Yes, the argument all comes to down to context.
In tonal music (perhaps I should say "mono-tonal"?), music written in keys or modes, polychords as such have no place. They would simply be an alternative way of looking at an extended chord (which is useful) - such as:

D
C7

to describe C13#11.
The fact that it can be described, or written, as a polychord, doesn't make it a polychord in practice (sound/action). It's still clear (from the sound) that it's one chord with one root note. It doesn't have two roots. And it functions within a simple tonal context, in a progression of other chords which also have one root apiece - and moreover work within a key with one tonal centre!

As jed says, true polychords depend on a polytonal context (AFAIK).
There's a great example from Stravinsky's Rite of Spring - a repeated polychord consisting of an Eb7 chord over an E major triad (written as Fb).
http://www.mhhe.com/socscience/music...ent/olc/28.htm
(Notice how many times this chord is banged out....)
It's full of what jazz players would call "avoid notes"; notes that disrupt (rather than enhance) any clear single chord function.
IOW, the intention is to superimpose conflicting chords, with contrasting connotations - not to just pile one triad on top of another to make a nice whole. Nor, on the other hand, to play just a random dissonance (as in leaning your forearm on the keyboard) - the particular sound of Eb7 over E major was clearly what he wanted.
It's got something in common with a jazz altered chord - the G and Bb representing a #9 and #11 on the Fb chord - but then there's a major 6 (Db) and major 7 (Eb) - definitely not a jazz altered dominant.
(You can play that chord in full on piano, but not on guitar - unless you have an 8-string guitar... and 8 fingers on your left hand...)

[P_J]

So Jon, people from Norwich would have no problems with the eight finger chord then ?

[SkinnyDevil]

So, I'll just direct him here so he can read the responses, which all seem to suppport my original assertion.

The sole exception is this:

The two triads don't need to be from different keys to be a polychord; D major of C major is a common polychord, but they're both found in the key of G.

While I may have been premature with an absolute statement saying they had to be from 2 differnt keys, this still sounds mistaken. If you're playing in the key of G and there is no implied bitonality, then why wouldn't a D-C more properly be called D11 (or a C-D more properly called a C13b5)?

My understanding (mistaken?) is that polychords proper require polytonality.

[Poparad]

Originally Posted by SkinnyDevil

While I may have been premature with an absolute statement saying they had to be from 2 differnt keys, this still sounds mistaken. If you're playing in the key of G and there is no implied bitonality, then why wouldn't a D-C more properly be called D11 (or a C-D more properly called a C13b5)?

My understanding (mistaken?) is that polychords proper require polytonality.

Well, first, you're reading those backwards. D-C would have a D triad on top, not on bottom, so it would compositely make up a D chord, not a C chord.

You don't need a completely bitonal situation to have a polychord. A polychord can be used in the midst of a progression using other kinds of chords, tonal or atonal. In the case of a completely diatonic progression, the polychord is going to function more as an extended chord (with the polychord being diatonic too, like D over C in the key of G), but it will still retain that polychord sound due to the voicing, which is a different sound than other extended chord voicings.

Here's an example of a progression from a song of my that uses a polychord though the phrase isn't polytonal. It starts out doing a bVI bVII I progression in B major (with the bVI and bVII borrowed from B minor). On the downbeat of the second measure, the notes B and D# are played, which imply that B major chord, but then when the rest of the notes are played, it ends up being Eb over E. The voicing sounds completely like a polychord in this case, and not like any kind of E or possibly B chords:

|-----------------------------------|-------------6---------------------|
|-5-----------------5---------------|-------------8---------------------|
|-------4-----------------6---------|-8---------8-----------------------|
|-----5-----------------7-----------|---------6-------------------------|
|---5-----------------7-------------|-------7---------------------------|
|-3-----------------5---------------|-7---------------------------------|

[Theodds]

A polychord, in the original sense of the word, is NOT just extensions. The reason why your buddy thinks you can do it as just extensions is because his example is extremly simplistic. You can't do the same with, say, a C-F# polychord, like in Petrushka. It gets even harder when you consider polytonal music, where the same lines are played in seperate keys at the same time.

[silent-storm]

Originally Posted by Theodds

A polychord, in the original sense of the word, is NOT just extensions. The reason why your buddy thinks you can do it as just extensions is because his example is extremly simplistic. You can't do the same with, say, a C-F# polychord, like in Petrushka. It gets even harder when you consider polytonal music, where the same lines are played in seperate keys at the same time.

yes, but where do you draw the line? C over F# is straight out of an F# simetrical dominant scale. That's the most used scale after major, melodic minor and harmonic minor and can easily be thought of as just a simectrical dominant chord rather then a poly chord.

Like has been said before I think a poly chord has a lot to do with how the chord is voiced rather then the actual notes in it. A triad is a very destinct and tonal sound in almost any situation, regardless of function.

[JonR]

Originally Posted by silent-storm

yes, but where do you draw the line? C over F# is straight out of an F# simetrical dominant scale. That's the most used scale after major, melodic minor and harmonic minor and can easily be thought of as just a simectrical dominant chord rather then a poly chord.

Like has been said before I think a poly chord has a lot to do with how the chord is voiced rather then the actual notes in it. A triad is a very destinct and tonal sound in almost any situation, regardless of function.

IMO it's more a matter of why you draw the line than where.
There is a difference between tonal and atonal music.
A C triad over F# in a jazz tune has a single harmonic function - it's just coincidence that it can be notated as if it was a polychord. The C triad is not really a C triad, functionally. It's the #11, b9 and b7 of the F# chord. IOW, in meaning and function, this is a single chord, not a polychord.

As far as I understand atonal music, the kind of dissonance represented by a C over F# polychord is non-functional - it's merely another sound in the palette. The dissonance does not drive towards resolution. At least, both triads have equal weight.
In the functional, tonal situation, the F# triad (in particular its root) rules. The C triad simply represents extensions on the F# - which, as i say, coincidentally form what can be seen as another chord.
You might add the #9 and say you now have a C6 chord (or Am7) over an F# triad.
Or you could go further describe the maximum number of chord tones as a Cm6 over an F#7. That would give you the b9, #9, #11 and 13 of an F#7 chord, the full symmetrical dominant scale (that some of us call half-whole diminished). It's still not a polychord, in the correct theoretical sense - even if you can write it as one.
(I don't think voicing is particularly relevant here. The notes of the C6 or Am7 would, most commonly, all be higher than those of the F# triad - but they could still go in any order. And one or two might be within the F# triad voicing.)

So - as I began by saying - it's a matter of WHY you draw the line. Do you mean "polychord" in the strict atonal sense? Or are you just using the term to conveniently describe a complex altered jazz chord ("mono"chord) with a simpler symbol? How much meaning do you attach to the term?
IOW, how fussed are you about proper theoretical terminology? There's no reason to care, really. We're just trying to use words and symbols to describe sounds.
That does mean the words and symbols should have consistent and clear meanings. But as long as context is understood - and usually it is - things are OK.
I have no problem with a chord like F#7b9#11 (in a functional harmonic context) being notated as:
C
F#
- as long as no one thinks we are really using polychordal (atonal) techniques; that the polychord symbol suddenly means we must be in a different musical universe.

At the same time, the "line" is a blurred one, a broad one. When Stravinsky used polychords, maybe he really did hear them the same way a jazz musician might. Maybe he did hear the lower chord as primary and the upper one as interesting altered extensions. Maybe he (or those interpreting his music) used the polychord notation as a simple way of representing those (single, complex) chords, for the same reason a jazz musician might. (Somehow I doubt it - I think the intention really was to combine two keys at the same time, not to work within one-key-plus-alterations.)

The difference between tonal and atonal is still paramount. But this polychord argument is (perhaps?) a matter of notation, not of musical meaning...