Chord Progressions Part II: Stability and Secondary Function!

This is taken straight from an E-mail I sent to Xel. It explains quite a bit, but assumes that you know some basic music theory. If you have any questions, send them to, and I'll try to answer them.

Okay.... here's the quick and dirty version...

Don't blame me if you find this confusing, it adds up to about a week or two of classes in a music theory class. ;)

But, of course, just send me any questions you have, and maybe we can figger it out. :)


Whenever you're composing in a key (which is always, unless you're writing 16th century vocal counterpoint), the key you're in has 7 'degrees' (a.k.a. notes of that key's scale) off which you can build chords.

(NOTE: Whenever you're writing a chord in relation to a key, use roman numerals to indicate the chord's degree. Use capital letters to indicate a major chord, minor letters to indicate a minor key. Put "7" on the end to indicate the addition of a minor 7th to the chord, and "maj7" to indicate the addition of a major 7th.)

In a major key, I, IV, and V are major; ii, iii, and vi are minor, and viio is diminished. (if the character after the vii is wierd, it's supposed to be a little tiny circle by the top of the letters... you know, like a degree sign from math. Option-shift 8 writes them on my keyboard).

In a minor key, V and VI are major, i and iv are minor, iio and viio are diminished, and III+ is augmented (The plus sign indicates an augmented chord - the fifth of the chord is sharped). You can sometimes use III major, but it's technically a borrowed chord from the relative major. If you didn't understand the last half of the last sentance, don't worry. :) I'll explain it later.

Okay. Next: All chords have various levels of 'stability,' which is based off: a) what kind of chord it is, and b) the chord's relation to the tonic (The I chord of the key you're in).

a) The stability of a chord is based on how 'nice' it sounds. Sort of. Major chords are the most stable, followed by minor chords. Major chords with major or minor 7ths added are next, followed by minor chords with major or minor 7th added. Last, and least, we have diminished and augmented chords. You will probably only rarely use augmented and diminsed chords, except for a few special cases I'll deal with later.

b) The more closely related a chord is to the tonic, the more stable it is. The idea is that, the more that a pecific chord indicates what key you're in, the more stable it is. I (the tonic), obviously, is the most stable chord. It's position makes it the most stable, even if it is minor. For the other chords, we classify the chords by their function to determine their stability relative to the tonic.

Pretty much all of what I said before is pretty much unneccesary for you to master chord progressions.... but it helps, because you have an idea of the underlying theory behind it. That said, chords are classified into 'functions' depending on what chords sound good before and after them.

TONIC FUNCTION: These chords give a strong sense of what key you're in, and are thus the most stable. The vi chord doesn't really do that as such... but it fits into chord progressions as if it were a I chord, so it belongs here.

Tonic function chords: I, i, VI (occasionally), vi

DOMINANT FUNCTION: These are the second-most stable chords, because a V-I progression (Or for even more effect: V7-I) really shows the suckers what key you're in. :) These chords proceed easily to tonic function chords, and moving to a tonic function chord from a dominant function chord will almost always sound good, if not particularily interesting. Definately a good way to end a piece, though.

Dominant function chords: V,v (rare), viio, V7

PRE-DOMINANT FUNCTION: These are at the third level of stability. They don't really move to the tonic easily (some exceptions), but they move to dominant function chords very well. Hence the name, pre-dominant.

Predominant function chords: IV, iv, ii, II (not very common), ii7

OTHER CHORDS: I didn't mention the iii/III chord, because I'm not really sure where it goes. The only chord I can think of that it flows easily to is vi. Well.... I tried it out, and I guess it goes to I sorta decently... (See [gb/e]p4[=eg/c]p4 and decide for yourself). I'm hesitant to call it a dominant function chord, though. Oh well. You figure it out yourself. :)

Okay! Now that we've got the main types of chords figured out, we can try to stick them into keys. Major keys are familiar to everyone, so a good place to start.

MAJOR KEYS: In a major key the chords you have to work with are I, ii, iii, IV, V, vi, and viio. The tonic function chords are I and vi, the dominant function chords are V and viio (and iii, sorta), and the predominant function chords are ii and IV. See? This isn't so hard!

MINOR KEYS: In a minor key the chords you have are i, iio, III(+) (The augmentation is optional... sorta. It deals with harmonic vs. melodic minor. If you didn't understand that, don't worry. It doesn't really matter.), iv, V, VI, viio. The tonic function chords are i and VI, the dominant function chords are V and viio (and III, sorta), and the pre-dominant function chords are iio, ii*7 (diminished circle with a slash (/) through it followed by a 7 = half diminished. (I don't know how to do this on the web) This means a diminished chord to which you've added a minor 7th (i.e. d minor half-diminished is [dfa./c]p4)), and iv.

Okay. So now you've got some chords, and can classify them. But how do you put them together?

Hmm. Have you ever seen a tetherball pole? Basically, it's a pole with a long cord attached at the very top, and at the other end of the cord is a volleyball, or something like that. As a kid (well... younger than I am now ;) ), I would go to one, wrap the ball-string around the pole one way, and try to whack the ball hard enough that it would unwind completely, and then wind up around the pole the other way. I know what you're thinking now: "Okay, that's nice, but what the heck does that have to do with music?" Well, the idea behind chord progressions is sort of the same.

Each song can be broken down into 'phrases,' which are sort of like musical 'sentances.' If a song is like an essay, verses would be paragraphs, phrases would be sentances, figures would be words (figure = a bunch of notes together. Really. :) ), and notes would be letters. When constructing each of your phrases, chord-wise, you want to start on a relatively stable chord, move out to less stable chords during the phrase, and work your way back down to something more stable for the end. Pretty much any sort of chordal movement is fine, when going to places of less stability. So feel free to jump from tonic chords to pre-dominant, or whatever the hell you want. Don't feel obliged to work your way backwards in order, or anything. When moving back towards stability, though, it's generally best to move sorta-in-the-right-order. Backtracking (say, from dominant function to predominant) and shifting to another chord on the same level (say, from dominant funtion to another dominant function chord) are both okay, and useful ways to avoid monotony.

An example chord progression using this method would be something like I-iii-vi-ii-IV-V-I. Try writing some chords using that progression, and try to make the highest note of each of the chords form a coherent melody. That is, if you removed all the notes but the highest one of each chord, it would still sound kinda nice. To do that, you might need to use inversions, which is basically when you play a chord, but mix up the octaves of the notes. So, instead of playing [=ceg]p4 (Called "root position"), you play [=eg/c]p4 ("First inversion") or [=g/ce]p4 ("Second inversion"). Understand? BUT..... be careful when using second inversion chords. The second inversion of I technically counts as a PRE-DOMINANT function chord, and NOT a tonic chord. This is because second-inversion chords are a lot less stable than they would be in root position. If you tried to end a song on I in second inversion, you'd probably find that it sounded wierd.


Okay! This is where it gets really interesting, but a LOT harder. So I'll try to explain it well, but I'm sure you'll be confused by the end. :/

If we only stuck to the 7 chords we have in a particular key, we'd rapidly run out of new things to do, and we'd have to write songs with such similar chord progressions that it wouldn't be long until Xepel leads a lynch mob after us. Soooooooo, why not use other chords, borrowed from other keys? It works prety well! So here's how to do it:

Basically, in its simplest form, you replace a chord with pre-dominant function with another chord or set of chords FROM THE KEY OF THE 5th DEGREE OF THE SCALE. That is, if you're in C major, instead of having a F major (IV) or d minor (ii) chord before a G (V) chord, use a chord from the key of G major. And, since a G chord has tonic function in G major, you'll want to use a chord that has dominant function in G major, since dominant function chords lead to tonic funtion chords. How you notate these 'secondary function' chords is as follows: you write the kind of chord you have in the key you wish you were in (To continue my example, I'd use a D7 chord, which is V7 in G major), draw a line under it, and write how that new key relates to your original key. For instance, in my example, since G is the 5th degree of C major, and since the G chord is major in C major, I would write V under the line. Thus, if I had to describe that chord, I could write V7/V. Which indicates that, in the major key a 5th above C major, this chord is a V7 chord. I realize I've repeated mysefl a few times here, but this part is tricky. But being able to describe the chords you write is VERY important, when trying to analyze what sounds good and what doesn't.

Try using it a few times, see if you can get the hang of it. Just little progression thingies like I-vi-V/V-V7-I. If you were in the key of C major, the chords would be C major - a minor - D major - G 7 - C.

You can even do strings of secondary function chords. For instance, remember that I (second inversion) has pre-dominant function. Thus, you could write a progression that went like I - I (2nd inversion) - V - I/V (2nd inversion) - V/V - V7 - I.

And, of course, you aren't limited to just doing secondary functions in the key of the V. Anything is fair game! For instance, I - V/vi - vi - ii - V - I. In the key of C, these chords would be C major, E major, a minor, d minor, G major, C major.

Don't forget that you don't have to go straight from pre-dominant to dominant function, either. Check out this one...

On Lyra: @140[%8=ega#]\E6E6[=c#ea]\A6A6[\a+f]\D=f[\g+e]\E=e[\b+d]\f4=d[\f#a+c]p4c[\G]B6A6G=e.E6[\ce]8=C8

This is in C major, and it would be a good ending to a blues or something jazzy like that. The chord progression is this:

iio/ii - V/ii - ii - I (1st inversion) - viio (2nd inversion) - viio/V - V -I

That is: e o (diminished) (ii of d) - A (V of d) - d minor - C major 1st inv. - bo (diminished) 2nd inv. - f# o (diminished) (vii of G) - G - C

Generally, it's easier to make secondary function chords off II, IV, V, and VI. III and VII are pretty tricky. And whether the chord is major or minor in the original key indicates whether the secondary key is major or minor. If the chord is diminished or augmented.... don't even try. It won't work. Really.

Remember, when you're using a secondary funtion chord, all the rules/guidelines for normal chord writing still apply... you just have to pretend you're in that secondary key. And, at least for that chord, you are.

Whew. I think that's enough for today. Hopefully this will be enough to get you started. Don't forget to email me if you have any questions.

Oh, one last thing. The degrees of the scale have special names:

I - tonic. II - supertonic. III - mediant. IV - subdominant. V - dominant. VI - submediant. VII - leading tone.

Be sure not to mix up the Dominant scale degree with Dominant Function. The chords based on the dominant scale degree HAVE dominant function, but they aren't the only ones that do. So be sure to use the correct term to say what you mean, when you use them.

And the really, really last thing. :) Most or all of my examples are in C major because it's the simplest one, but, of course, these tips work in every key. So be sure to try them in different keys too, until you get the hang of it.

Whew. That only took me 3 hours to write. ;)

Go back to my music.