Chord functions of III and VI in minor key

[thared33]

Jazz guys usually appear to be of the consensus that the III in minor is more of a tonic and that the VI is a pre-dominant. However, more than a few times I’ve seen some classical type musicians say that the III is more of a dominant and that the VI is a tonic.

Can someone explain why I’m seeing different functions of these chords between jazz and classical guys?

[ragman1]

Which minor?

[thared33]

Aeolian.

[thared33]

Concerning the VI chord, I read that it contains a note from the iv chord so it could be considered pre-dominant because of that. I also read that since it’s a Tritone away from the ii that it could be considered pre-dominant. But that confuses me. I thought a tritone substitution was always a half step above the target chord. That would make it an Eb chord in the key of Am. It’s true that Ab is a tritone away from the ii chord though. I’m just not sure how that makes it pre-dominant.

[christianm77]

Interesting, not sure if I know enough about classical functions to comment though. I see it the jazz way for sure.

[christianm77]

I think the 'classical' approach is more based on taking the degrees of major

I - T
II- S
III- D/T
IV - S
V - D
VI - S
VII - D

And applying them to minor, regardless of chromatic alterations? So Ab in Cm is a Tonic function, in this understanding.

For me, I can't help but hear that minor 6th - C-Ab as an unstable interval in the context of Cm. Much like the 4th in C major, it's consonant in isolation but dissonant or dissonant-seeming in context. So chords that have that note tend to sound subdominant or dominant in function.

Here's another way of looking at it - minor as relative to major, so
I, Am - VI of C - T
II, Bm7b5 - VII of C - D
III, C - I of C - T
IV, Dm - II of C - S
V, Em - III of C - D or T
VI, F - IV of C - S
VII, G(7) - V of C - D

So (b)III and (b)VI are tonic and subdominant here.

This seems a lot closer to how I hear it. But I don't know if classical guys ever think this way?

Also, Erno Lendvai's pitch axis theory would class a bIII as Tonic function, and bVI chord as subdominant.
Axis system - Wikipedia

[ragman1]

Jazz guys usually appear to be of the consensus that the III in minor is more of a tonic and that the VI is a pre-dominant. However, more than a few times I’ve seen some classical type musicians say that the III is more of a dominant and that the VI is a tonic.

Can someone explain why I’m seeing different functions of these chords between jazz and classical guys?

Can someone explain why the III, which is CM7 in A aeolian, should be considered a dominant chord?

[matt.guitarteacher]

However, more than a few times I’ve seen some classical type musicians say that the III is more of a dominant and that the VI is a tonic.

This sounds like a description of MAJOR... Granted, minor CHORDS in a major KEY, but major nonetheless. I've never threads minor talked about that way, but there's a lot I haven't heard I guess. It would be helpful to have an actual source etc.

Anyway, there's not really a III or VI in natural minor anyway. It's bIII and bVI.

[christianm77]

This sounds like a description of MAJOR... Granted, minor CHORDS in a major KEY, but major nonetheless. I've never threads minor talked about that way, but there's a lot I haven't heard I guess. It would be helpful to have an actual source etc.

Anyway, there's not really a III or VI in natural minor anyway. It's bIII and bVI.

That’s what they mean.

It is a thing - Unlocking the Mysteries of Diatonic Harmony - Art of Composing

[thared33]

This sounds like a description of MAJOR... Granted, minor CHORDS in a major KEY, but major nonetheless. I've never threads minor talked about that way, but there's a lot I haven't heard I guess. It would be helpful to have an actual source etc.

Anyway, there's not really a III or VI in natural minor anyway. It's bIII and bVI.

I thought it was obvious that I meant bIII and bVI.

I've definitely read that a bIII can be a dominant. I'm not sure what they're on about. Other than that, it seems like a tonic.

I'm mostly curious about the bVI stuff I posted above.

[christianm77]

Well my approach is simple. In the key of C or Am, any chord with an F in is either subdominant or dominant in function, the latter if dissonant the former if consonant.

Anything else is a tonic chord. That includes the G triad.

But that’s my way of looking at it. So F is subdominant chord in both C and Am

[thared33]

That’s what they mean.

It is a thing - Unlocking the Mysteries of Diatonic Harmony - Art of Composing

The minor chart on that page says exactly what I mean. III a dominant and VI a tonic.



I wonder why it's different for classical.

PS: On the major chart, I wonder why the iii can be a pre-dominant. Hmm...

[thared33]

Since the bVI chord is a Tritone away from the ii, it can be considered pre-dominant. But that confuses me. I thought a tritone substitution was always a half step above the target chord. That would make it an Eb chord in the key of Am. It’s true that Ab is a tritone away from the ii chord though. I’m just not sure how that makes it pre-dominant.

Can someone comment on this tritone thing?

[christianm77]

The minor chart on that page says exactly what I mean. III a dominant and VI a tonic.



I wonder why it's different for classical.

PS: On the major chart, I wonder why the iii can be a pre-dominant. Hmm...

Clearly the minor is the same as major idea is quite a big deal in classical theory, it’s why they have harmonic minor. So it makes sense they would assume the minor degrees would have the same function.

But I don’t know if it’s true for all versions of classical harmony. As I said if you look at minor as a part of the relative key, the jazz functions seem to come from there.

Or Erno Lendvais theory.

[christianm77]

Concerning the VI chord, I read that it contains a note from the iv chord so it could be considered pre-dominant because of that. I also read that since it’s a Tritone away from the ii that it could be considered pre-dominant. But that confuses me. I thought a tritone substitution was always a half step above the target chord. That would make it an Eb chord in the key of Am. It’s true that Ab is a tritone away from the ii chord though. I’m just not sure how that makes it pre-dominant.

Yeah I don’t think of it quite like that. I think ‘family of four’: there are four connected chords in C/Am for example:

G7 Bm7b5 Dm7 Fmaj7

These can be freely exchanged with one another

Bm7b5 and Fmaj7 for instance

All these chords have an F. They all have subdominant/dominant function which is kind of the same thing to an extent, you can regard a dominant chord as a dissonant subdominant chord.

This reflects the weakened role of the non tonic chord tones in jazz. The D, A and B can all be blended into the tonic chord, but not the F

Furthermore these chords are subject to tritone substitution and minor third relationships

[Jazzstdnt]

I thought it was obvious that I meant bIII and bVI.

I've definitely read that a bIII can be a dominant. I'm not sure what they're on about. Other than that, it seems like a tonic.

I'm mostly curious about the bVI stuff I posted above.

Joe Mulholland and Tom Hojnacki explain it as follows:

"Chords that contain scale degree b6 as a primary chord tone and do not include the leading tone are mostly responsible for the sub-dominant minor sound. This results in more subdominant options in minor key harmony than in major key."

Sub-dominant chords from an Aeolian source, which can be used interchangeably in the pre-dominant position:

II-7b5
IV-7
bVIMaj7

[ragman1]

Sorry, no one's answered my question yet. How can a M7 chord be considered a dominant chord?

(As someone's quite rightly pointed out there's the major family and dominant family. A M7 does not belong to the dominant family! The VI, on the other hand, is a bit dubious, as we know)

[Jazzstdnt]

Sorry, no one's answered my question yet. How can a M7 chord be considered a dominant chord?

(As someone's quite rightly pointed out there's the major family and dominant family. A M7 does not belong to the dominant family! The VI, on the other hand, is a bit dubious, as we know)

Do we have a source other than the above post that posits that? I can't find one.

[christianm77]

Joe Mulholland and Tom Hojnacki explain it as follows:

"Chords that contain scale degree b6 as a primary chord tone and do not include the leading tone are mostly responsible for the sub-dominant minor sound. This results in more subdominant options in minor key harmony than in major key."

Sub-dominant chords from an Aeolian source, which can be used interchangeably in the pre-dominant position:

II-7b5
IV-7
bVIMaj7

That’s very much how I hear it too. In A minor the Aeolian note is F, see above....

[christianm77]

Sorry, no one's answered my question yet. How can a M7 chord be considered a dominant chord?

(As someone's quite rightly pointed out there's the major family and dominant family. A M7 does not belong to the dominant family! The VI, on the other hand, is a bit dubious, as we know)

I think in the classical world we wouldn’t be thinking of major sevenths but plain major chords.

[thared33]

I think people mean the bIII triad is dominant rather than the extensions. I’m still wondering why that triad is considered dominant. I would also still like to hear more of an explanation for why the bVI is sometimes considered a tonic.

And most importantly, I’ve read that the bVI is a tritone away from (or is the tritone substitute of?) the ii chord in both major and minor, so it’s considered pre-dominant. Can someone explain that?

[ragman1]

Do we have a source other than the above post that posits that? I can't find one.

Er...

a few times I’ve seen some classical type musicians say that the III is more of a dominant

[ragman1]

I think in the classical world we wouldn’t be thinking of major sevenths but plain major chords.

Major, major7, major schmajor, a major is NOT a friggin' dominant chord.

[thared33]

The bIII triad has only one note in common with the V so I'm still having trouble understanding. What progression are you playing there?

[christianm77]

Major, major7, major schmajor, a major is NOT a friggin' dominant chord.

What about when it’s on degree V of the major scale? A classical theorist would consider that a dominant chord.