Lesson 12: Roman Numeral Theory 3: Chordal Tendencies 1: USC 23

Hey everyone, sorry this took so long, but I actually wrote this post in entirety, saved it, closed the window, and when I went to edit it, to give it a last once-over and publish it, it had regressed to the save before I wrote it.

Ok, so finally let's talk about chordal tendencies.

We already learned about cadences, and that's a good starting point to think about this.  You'll notice that all cadences with the exception of the Plagal, which is a lot weaker than the others, and is normally used as sort of an after-cadence flourish, they all involve V in some way.  And while one ends in V(Half Cadence), we'll note that the V-anything other than I cadence is referred to as the deceptive cadence.  That's because the V-I motion is so strong in tonal music that V-not I is all "HOLY SHIT WHAT THE FUCK IS GOING ON", or rather, it used to be.  Now we're sort of used to it and it's no big deal, but it used to be like, whack as shit.

So the basics of this are actually really simple.  Each diatonic chord has "natural" progressions from it(and therefore to it as well).  They are as follows:

I   -  goes to - Anywhere
ii   -  goes to - iii, IV, V
iii  -  goes to - IV, vi
IV - goes to - ii, V
V  - goes to - I, vi
vi  - goes to - ii, IV, V
vii^o - goes to - I

Ok, that's pretty simple, right?  Now, it's also pretty damn restrictive, and in fact, you can go from really pretty much any diatonic chord to any diatonic chord without it sounding too jarring(The exception being V7 and vii^o, because of the collapsing tritone(Yeah, I know, I'll get to it.  Maybe not this lesson, but soon)), but these are the ones that work the best and pretty much will always work.

For minor, we get the following:

i     - goes to - Anywhere
ii^o  - goes to - III
III  - goes to - iv, V, VI
iv   - goes to - V, VI
V   - goes to - i
VI  - goes to - iv, III, V
vii^o - goes to - i

I'm a little more shaky on those, and can't find my theory book that mentioned those, but I'm pretty sure that's right.  Also, you'll notice, as I mentioned before, that V and vii^o are altered in minor for voice leading purposes.  We raise the leading tone(Harmonic minor scale) when playing these because we get the strong.... well we get the strong leading tone.

Ok, so that's the basics, and not as big as I kept building it up.

But hey.... like I said, it's pretty restrictive, right?  For that matter.... hey wait, nothing leads to vii^o.  Well, it's time to learn about substitutions, which are the first level of added complexity to basics of tendencies.

Let's look at a V7 chord in C major.  It has the notes G-B-D-F.  Now let's look at a vii^o in C major.  It has the notes B-D-F.

What we can do is essentially use a vii^o in place of a V7, or substitute the vii^o.  By doing this, we can treat the vii^o entirely as though it were a V chord, so we can approach it from ii, IV, or vi, and it can go to I(and vii^o is one of the few substitutions where leaving it is a little different than the V chord.  The vii^o really doesn't go well into the vi chord, which is why evne though nothing leads to it, it still has its own place in the list of tendencies) While in this case, the vii^o simply omits a single note, there are other substitutions I want to look at that change things up a little, and can be used more fully.

The first one I want to look at is the use of inversions as substitutions.  As an example, instead of the strings I used for the last example, here's a brass band:
Click here to listen to iii v I6.mp3
Now, this basically is the exact same figure twice, right?  Except that third chord sounds different.  Just a little, and it still works, but it sounds happier and move conducive to upwards motion in the second time.

Well, that's because we use an inversion of the I6 chord in the example.  While the I chord can go anywhere it wants anyways, the ii chord does not lead to the I chord.  However, since the I6 chord is only one note away from the iii chord(That is to say, they share the 3rd and 5th scale degree and only differ as the Tonic is in the I chord and the leading tone replaces it in the iii chord).  Now, the first inversion of chords tends to have a very "pretty" sort of sound, they sound nice and open, and they tend a little upwards.  Second inversions tend to sound a little unbalanced and unstable, and in certain cases can sound like a suspension of a different chord(for instance, in the cadential 6-4 from last lesson, even though it's a I6-4, it sounds like a V chord that just has the 6-4 above it that then resolves down)  Personally, I love first inversions and sub-ing in first inversion chords, I just love the sound, and having them in open voicing I always think just sounds awesome and is a really useful tool.

So with substitutions, we open up those restrictive tendencies a lot, because now, for instance, if instead of a iii chord we want to use a I6 chord?  Well we can.  So now anything that leads into iii can also lead into I6.

Now, not all substitutions of inversions will work, and they won't work 100% of the time, but here are the most common substitutions:

chord - substitution
iii - I6
vi - IV6
V - vii^o


Ok, pretty simple still.

You'll all notice though, that we're still just dealing with groupings of two chords.  x -> y is fine, but that's only a small part of progressions.  Well, we can theoretically tie them together any way we want, but there are a few groupings of chords that are very common in music and have very recognizable sounds and uses.  We're going to refer to these as Chord Paradigms, and they're going to be what the rest of this general unit is about, because they're pretty heavy.  Essentially though, they're simple progressions that are fairly common.

I'm going to end this lesson here, even though it's fairly short, and start on Paradigms next lesson, with the most common ones and their sounds.  We might have a bit of a delay again between these as well, because I'm pretty busy, I'm going on tour the week after next, and I have a lot of examples to prepare sound files for.