Chord names and modal harmony

[rickosound]

Is it nonsensical to use the terms supertonic chord, mediant chord etc when refering to chords in a modal rather than tonal context.

Dm Em F G Am Bdim C
i ii III IV v vi VII

[Zatz]

Welcome to IBreatheMusic, rickosound!

You're entering with a very good question ;)

IMO, it depends on the mode.

Let's just consider this example with D Dorian.

In an ordinary C major we have the following function arrangement:

I - C(Tonic)
ii - Dm(Supertonic)
iii - Em(Mediant)
IV - F(Subdominant)
V - G(Dominant)
vi - Am(Submediant)
vii - Bdim(Leading tone)


Every function on its degree plays its unique role within a certain progression:

* Tonic, Mediant & Submediant are related to Tonic Group
* Supertonic, Subdominant & Submediant - to the Subdominant group
* Mediant, Dominant & Leading tone - to the Dominant group

As you may have noticed - these groups share one chord - they kind of intersect due to common tones. For ex., Mediant Em consists of E, G, B sharing E & G with C major chord (tonic) and G & B with the Dominant G - G, B, D.

The question is now - can we automatically leave it all as it is after switching to the new mode... Let's see.


i - Dm(Tonic) [+]
ii - Em(Supertonic) [+]
III - F(Mediant) [+]
iv - G(Subdominant) [+, provided its triad]
v - Am(Dominant) [+/-]
vi - Bdim(Submediant) [-]
VII - C(Subtonic) [+]


Is it really ok now?

* Dm - tonic. Passed the test - we'll take it for granted.

* Em - supertonic - why not. Passed.

* F - mediant - pretty much like the case with regular minor. Passed.

* G - subdominant - like in minor scale too. OK here, but not with G7 chord that will lead back to C major destroying the modal flavour. Passed, provided it's just a triad.

* Am - dominant. Very weak due to absense of the leading tone. Though in natural minor there's a similar situation. Passed with a slight doubt.

* Bdim - submediant. NO. The main reason is that submedian should work as a tonic substitution cos, as we stated earlier, it is related to the tonic group. Bdim is acoustically unstable chord cos there's flat 5 in it creating a tritone interval with the root.

* C - note that in this case it's called subtonic - just a tradition to call the bVII degree in minor scales. Works as an approach chord perfectly and is widely used in such a context.

Similarly, you can analyze the rest of the modes.

Zatz.

[xenor]

Actually.. there are two approaches to the modal harmony.. One is classical modal and the other is jazz modal..

As Perchietti states in his book; "20th century harmony" the modes are - as we all know - ionian, dorian, phrygian, lydian, mixolydian, aeloian, locrian. Ionian and Aeolian are the maj and min scales and locrian has a flat 5 so will leave them out now. If we compare the sounds (and the sharp/flat quality + the place of min2nds in the tetrachords) will see that dorian and phrygian are minor modes and lydian and mixolydian are major modes.

So; if we compare the dorian and phrygian to the natural minor scale; will see that, the different note is b6 for dorian and b2 for phrygian. I f we compare lyd and mixo modes to the maj scale; we'll see that different note is #4 for lydian and b7 for mixolydian. These different tones are characteristic tones of the modes. If we harmonize these modes we'll see that these characheristic tones occur 3 times; once in a dim triad and twice in a maj or min triad. Those 2 maj or min triads are primary chords and can be used as dominants there's the tonic and the dim chord. The remaining chords are secondary chords. Just like tonic, subdominant and dominant in a major or minor scale...


In Modal Jazz harmony; the scales are not use as we use. The color tones are used to build the chords and the main concern is to connect the chords; even if they not relate to each other in a diatonic way.

Hope this helps.