Switching to major or minor equivalents in progressions

[Caleb]

I've been taking in some of the posts in this forum and this is really helping me understand what I'm doing with my progressions.

I have a question regarding enharmonic progressions.

If I have a minor key - eg Cminor I have the following enharmonic chords:

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i    - Cmin
IIo  - Ddim 
III  - Ebmaj
iv   - Fmin
v    - Gmin
VI   - Abmaj
VII  - Bbmaj

I find that if I play Cmin7 followed by F7, it sounds nice to me.

Another example is going from Cmin to Gmaj to Cmin - sounds nice to me.

I don't even mind the Cmin to Ebmin and then back to Cmin.

These are not enharmonic progressions, but I was wondering if there was any progression theory to back up why I would like those changes, or is it just a case of, pick a chord and if you like it use it?

Regards
Caleb

[Toxikator]

When you say Cmin7, do you mean the minor-minor 7? When you say F7, do you mean the major/minor (dominant) 7?

It might help if you spell them out. If they're the chords I'm thinking of, it would seem that the only deviation from key is the A in F7... and depending on what chord follows, it could easily be classified as a secondary dominant (consider Cmin7-F7-BbMaj-Cmin)

Cbmin to Ebmin to Cbmin again is a textbook chromatic mediant chord for a minor key, you should check out the "my first post-theory homework" thread for a more detailed explanation.

Cmin-Gmaj is even MORE textbook, this time for the harmonic minor scale form (where the 7th is raised, or in the case of Cminor the Bb is made to a B. This makes the V chord, or G, a major chord instead of a minor chord.)

BTW you keep saying "enharmonic"... do you mean diatonic?

[Caleb]

Okay, so to settle on a definition for Chromatic mediant, we would say:

A chord which is of the same quality as the tonic (major/minor) and whose root is either a major or minor third or sixth of the scale.

Chromatic mediants usually follow the tonic chord and are usually followed by the Tonic, Dominant, or another mediant/submediant.

So from this definition, if I have a Cminor key then the chromatic mediants would be Ebmin and Emin for the third. What would they be for the 6th, Abmin and Amin?

For the Gmajor, if you use the harmonic form of the scale you get variations including Gmajor in the Cminor scale. Thanks - that makes sense. Does that mean that there are other variations when "switching" to the harmonic minor scale - Eb aug for example?

When you say Cmin7, do you mean the minor-minor 7? When you say F7, do you mean the major/minor (dominant) 7?

I believe that's right. I think I'm using the accepted representation yes?

If they're the chords I'm thinking of, it would seem that the only deviation from key is the A in F7... and depending on what chord follows, it could easily be classified as a secondary dominant (consider Cmin7-F7-BbMaj-Cmin)

I kinda moved that way - Cmin7 - F7 - Cmin7 - F7 - Bb7 - Ab - Cmin.....
I don't really understand what a secondary dominant means in this case, but I think that's where terminology starts to confuse me.

I think my use of enharmonic is erroneous in my first post - please ignore.

Regards
Caleb

[Caleb]

I just wrote down a small list of chords which might be useful to me when composing in C minor.

In another thread there was a discussion about using bIII and bVI chords as alternatives when composing in a major key. I translated this in a minor key to mean bI and bV - I hope that's correct.

Anyway - the observation I'm making is that the flattened root notes of the triad for bI and bV are the same flattened 3rds in the chromatic mediant chords, Ebmin and Abmin.

Is that a vaguely interesting observation - or not really?

Regards
Caleb

[Toxikator]

I'll try to tackle this as best I can:

The harmonic minor form is used because it creates a stronger harmonic movement. you DO get other chords... namely, the III becomes a III+, the v becomes a V, and the VII becomes a viio. All of these chords progress more naturally to the next chord in the circle than their natural counterparts; that said, it is valid to switch amongs the forms as you see fit (just try to keep the raised 7th away from the natural by a few notes).

In C minor, the chromatic mediants are indeed Emin, Ebmin, Amin, and Abmin.

A secondary dominant is like a temporary modulation. I don't know how much you know about circle progressions, but the motion from the dominant to the tonic (V-I) is a very powerful one. So powerful, in fact, that it makes it easy for the human ear to disregard the chromaticism of secondary dominant chords.

Secondary dominants are when the chord you play is out of key... because it is IN the key of the chord that follows it.

In the key of C major, for example, the chord DF#A (Dmaj) does not exist. However, it IS the V chord of the key G major. Therefore, the progression DF#A-GBD (Dmaj-Gmaj, V-I) is a very strong one. And it just so happens that GBD IS in the key of C. So if you were to play DF#A in the key of C, followed by GBD, then the DF#A would be a secondary dominant; a chord which acts like the dominant chord in the key of the chord that comes after it.

In CMaj, I-II-V-I is a nice progression; since DF#A is only out of key by one note, it sounds rather natural, and is resolved by the resolution to G, which in turn resolves nicely to C. Try it out sometime.

The bIII and bVI are actually chromatic mediants, and very common in major keys. When translating them to minor keys, don't translate that to mean bI and bV... those are the relative chords, but chromatic mediants are done by parallel. Their counterparts in a minor key would be the niii (in Cminor, Eminor) and the nvi (in Cminor, Aminor)... those being the more common chromatic mediants (though the biii and bvi are used, just as the nIII and nVI are used for major keys...)

[Caleb]

A secondary dominant is like a temporary modulation. I don't know how much you know about circle progressions, but the motion from the dominant to the tonic (V-I) is a very powerful one. So powerful, in fact, that it makes it easy for the human ear to disregard the chromaticism of secondary dominant chords.

Secondary dominants are when the chord you play is out of key... because it is IN the key of the chord that follows it.

In the key of C major, for example, the chord DF#A (Dmaj) does not exist. However, it IS the V chord of the key G major. Therefore, the progression DF#A-GBD (Dmaj-Gmaj, V-I) is a very strong one. And it just so happens that GBD IS in the key of C. So if you were to play DF#A in the key of C, followed by GBD, then the DF#A would be a secondary dominant; a chord which acts like the dominant chord in the key of the chord that comes after it.

OK - I think I get it.

So going from the C major scale, secondary dominants would be:

D followed by G

Would the dominant of any other chord in C also apply - eg:

Bmin followed by Emin?

It seems to work if I play something along the lines of:

I - vii - iii - IV - I - V.

Regards
Caleb

[Toxikator]

Yes it would (Bmin followed by Emin)

Here's the thing to try to keep in mind, though; secondary dominants should at least be somewhat related to their diatonic counterparts. DF#A works after C because DFA works after C. If you were going to play Bmin in Cmaj, you would want to do it after, say, GMaj, because the motion from G to B is relatively strong in a circle progression...