How does the concept of functional harmony help me pick the next chord while composing?

Question

I'm trying to understand the concept of functional harmony as it pertains to composing chord progressions, in order to compose my own progressions.

I've read a few articles and watched some videos, I think I get the basic idea that some chord classes lead to and from other chord classes (T, P, D). This image sums up what I understand so far quite succinctly. I got it from here.

Fundamentally though, I don't understand whether this concept is saying "Do this", or "Have you noticed how music tends to do this?"

Because if the latter, then the concept of functional harmony is a great ice breaker when trying to pick someone up at a bar, obviously, but not very useful for actually writing music.

If it's the former, and it's narrowing my list of "what should the next chord be" candidates while writing, that's great, but then I have to wonder why almost none of my favorite progressions fall in line with that graphic, as I understand it.

For instance, Creep, by Radiohead: G-B-C-Cm. The article tells me that I can move right as far as I like, so no problem going from the tonic to the III. Then no problem going from III to IV, we're still moving right. But then... we just go from IV to iv? Huh? I thought we were in G Major?

What about Jimi Hendrix's Little Wing? Em-G-Am-Em-Bm-Am-G-F(wtf?)-C-D. Why can we move from dominant to pre-dominant in the first place? That basically means we can move from any of our three chord types to any of the others, except for pre-dominant to tonic. But we do that in this progression anyway when we go from Am to Em. And then we go Am to G, and it doesn't say we can do that anywhere. Then we go to F? The worst possible chord we could pick, and it turns out to be the best, most sweetly harmonious sounding part of the progression? It's not a passing chord, he lays on the F chord for a bar, and plays F major pentatonic licks over it.

How does chord function explain any of that?

More importantly to me, how would thinking about chord function have helped me write those chord progressions?

Answer 1

Trying to answer simply. All music theory tries to explain what has happened - to be helpful to future musicians. Like most laws, when a certain thing happens time and time again, and can be proved, its theory changes to a law. (Boyles law, Charles law et al). Music has no such laws, as it's still in (and probably will be for ever!) in the theory stage.

The movement of one harmony to another to another has been studied, and there are certain patterns that crop up time and time again. If it ain't broke...But that never means that other, possibly more interesting sequences, aren't going to work. In fact, they're usually the ones that stand out, as in your examples.

Working formulaically produces music that's not bad, but relying on functional harmony 'rules' means you're treading in furrows that have already been ploughed deeply. Ruts if you like. It's often been said that one cannot break the rules properly until one knows the rules properly, and that's what's important here. Know the 'rules' of functional harmony, then go beyond. The other old adage is that if it sounds good, it probably is. Doesn't come truer than that. So, in composing, functional harmony is a good start point - and will be used a lot - but there's no reason to use it as a crutch. Break out from the mould, after all, that's what a lot of the more notable composers have done.

Answer 2

that basically means we can move from any of our three chord types to any of the others.

Yes, you can combine any chords together. Jimmy Hendrix and Palestrina (or any other Rock - or Renaissance musicians e.g. didn't compose typical functional music. You can make statistics and discover yourself that functional harmony has been developed through hundreds of years while there was always other chord or non chord music without functional harmony.

2.

Fundamentally though, I don't understand whether this concept is saying "Do this", or "Have you noticed how music tends to do this?"

There are rules that the leading tones should be resolved half step wise up (or down): the tritonus BF in a V7 chord (GBDF) "wants to" (or should - but must not) resolved B up to C, F down to E). If you go through the circle of fifths you will always find this voicing! (Look up the voice leading of the chord progression e.g. C->E7-A7-D7-G7-C ... you will find that the tritone of the 3rd and the b7 leading down in semi tones to the 7th and 3rd of the next chord. This is one important fact of the functional harmony (the 5th fall sequence).

3.

the concept of functional harmony is a great ice breaker when trying to pick someone up at a bar, obviously, but not very useful for actually writing music.

Now there are other rules like the substitution by relative chords: They contain common tones like e.g. iii EGB is related with the dominant GBD (GB) and the tonic CEG (EG). In a club you are looking for an icebreaker of commonness and relations as any subject like "coming from", "being fan of", "political party" and other connections. In music we have the parallel chords, the relative chords, the mediant chords, which are related and can be easily connected. Understanding these terms and functions you can explain almost any progression of yours above. So to understand the concept of functional harmony you have to look up all these 3 chord relations and the tritonus substitution.

And if there is no connection or explanation remind section 1.

Answer 3

In both the examples you shared, the key of using those chords (Cm in the key of G Major and F in the key of G Major) is modal exchange.

The chords don't belong to G Major (Ionian mode) but they both belong to G Minor (Aeolian mode). So it results as a short modulation to G minor, spicing up the progression.

Another nice chord you may find in the context of a G coming from the same scale is Eb major, like in the song Gravity by John Mayer.

Answer 4

The flow chart you linked looks like a copy of...

...which is from Kostka/Payne, Tonal Harmony. But with some German theory sprinkled in. Combining the American and German theory might get a little confusing.

The basic idea of American functional harmony is: pre-dominant (ii, IV, etc.) moves to dominant (V, viio) moves to tonic (I). You could also generalize it as root movements by descending fifth with two caveats: I IV V I is a harmonic sequence of two descending fifths motions [I IV][V I] and V, vii0, and viio7 can all be viewed as portions of a larger dominant chord.

...I don't understand whether this concept is saying "Do this", or "Have you noticed how music tends to do this?"

I think most theorists will say it is a matter of "have you noticed...", and it's specifically about European music from around 1650-1850.

...I have to wonder why almost none of my favorite progressions fall in line with that graphic

It's a generalization for European music, 1650-1850-ish. It's origin is in the Christian Church and aristocratic court music. It's often called the Common Practice period. At that time composition was fairly strict, but that changed over time. Elements of the style crossed borders too. You can follow a line from the European hymn to America to the spiritual to the blues to rock. It's a long line. Some elements of the old European strict style persisted, other were abandoned.

...Radiohead ...Jimi Hendrix ...Why can we move from dominant to pre-dominant in the first place?

The IV, I, and V chords are the primary diatonic triads. Those chords used in any order will give a clear sense of tonality. But, if we are strict about functional harmony, V IV is backwards, a retrogression. Rock/pop music isn't strictly functional. It's as simple as that. You can move from dominant to pre-dominant, because the music isn't strictly function, and that doesn't necessarily undermine a clear sense of tonality.

...But then... we just go from IV to iv? Huh? I thought we were in G Major?

That's called a borrowed chord or mode mixture.

A single flow chart or cheatsheet won't cover everything about tonal/functional harmony. If you try to rely on just that chart, you will keep having questions. Get a textbook like Kostka or Walter Piston. Bach's Chorales are probably the most comprehensive and densely packed resource to see it all in action.

...How does the concept of functional harmony help me pick the next chord while composing?

It gives you a basic idea of norms. Essentially the charts tell you chord roots commonly move by descending fifths and also by descending thirds. That certainly narrows the scope of choices. But, both the Kostka chart and the one you linked indicate the I chord can go to any other chord. That's not much of a guide.

I think the problem with both charts is they don't convey the importance of voice leading and cadences in Common Practice. Charts like this certainly aren't how musicians learned harmony at that time. They are not wrong, but in terms of making choices to compose a lot of information is missing.