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23. Hamonize & reharmonize

For several episodes we've seen different types of chords and how to use them, either by taking some chords from one tonality or by borrowing chords from other tonalities to make great chord progressions.

But you don't always start a song with the chords progression. Sometimes you start with a melody and you just want great chords to support it. So today I'd like to take some time to talk about strategies and things to keep in mind while harmonising or reharmonising a melody.

So in this video, we'll try to take a bit of everything we saw in this series, and apply it to harmonize a melody.
To make it easier, a few months ago, I've made a document gathering a lot of useful information we've seen. I also made a video summing everything up, explaining how that document works.

So let's begin.
So let's say the melody we want to harmonize is this one.


The first step would be to find the tonality it could be in. So we would have a set of chords to start with.

So if we check the notes of the melody, we have C#, D,  E, F,  G,  A and Bb. So we have 7 different notes already. Which is good, that means we may already have all the notes of the scale we're going to use.
And to find this scale, we're going to use the circle of fifth.

So we have one flat note, which is B. And we have one sharp note, which is C.

If we look at the minor and major tonalities around the circle of fifth, on the flat side, we have a tonality here with one flat note that is Bb, because that's the first note to become flat.
The problem is in this scale, the C is natural and not sharp.


Now if we look back at our melody, we notice that it begins and end on a D. Which is a good clue that the D has a central role in our scale.
And in the D natural minor scale, the 7th note, C, can be raised by a semi tone, so the scale becomes the D harmonic minor scale.

So the D harmonic minor scale is the scale we were looking for, which means our tonality is D minor.


Now the best way to harmonize this melody would be to create a clear chain of chords, that could fit the notes of the melody.

The best way to start would be to define which chords we can use in the tonality we have.

So in D minor, the Ist degree, the chord made from the first note of the scale, is Dm. The IInd degree is E diminished. The IIIrd degree is F major. The IVth degree is G minor. The Vth degree is A minor, but it can also be A major, that's when the C becomes C#. Or you can use a A dominant 7th on this degree as well. Then the VIth degree is Bb major. And the VIIth degree is a C major chord.


From there, you can start assigning chords to some parts of  your melody. The notes of your melody being either the root note, the 3rd or the 5th of the chord you use below it.

So let's see how these chords could fit our melody.
In the first bar, we have the notes D, F and A, which are the notes of a D minor chord. So let's begin with that.
Then we have G, F and E. We can decide to neglect the F because it is on a weak beat, so it would be just a passing tone between the G and the E. 
The G and the E can the root and the 3rd of a E chord, or they can be the 3rd and the 5th of a C chord.
But here I decided to consider them as the 5th and the 7th of a A dominant 7th chord, by adding the root note A and the major 3rd C#. It's a chord that can be used on a Vth degree, and that resolves well on a degree I.
And sure enough we have a D at the end of this bar, so we can lend on a D minor chord here.


Having this I - V - I chord progression can really accentuate the tonality of D minor, with this authentic cadence V to I that is very conclusive. It's a good way to establish our tonality.

Then we have a D and a Bb, which can be considered as the 5th and the 3rd of a G minor chord.
And the last bar starts on a C#, which is the 7th note of our scale that is raised by a semi-tone. And this alteration is often seen in a minor tonality on the Vth degree, when this chord that is normally minor becomes major.
So let's put a A dominant 7th here, so we have in this bar the root note A, the major 3rd C#, the 5th E and even the 7th G. 

This is a good example to show that you don't always need to harmonize every note of your melody, especially when they move stepwise from one to the other.


With these 2 authentic cadences A7 to Dm, that's a very tonal chord progression that really establish the tonality of Dm.

But as I said earlier, there are always several ways to harmonize the same melody. So here is another example of how we could harmonize it.


We still have the Dm at the beginning, the A7 at the end and a Gm in the middle.
But the first chord is cut in half, so the last F of the first bar is now part of a F major chord.
the second bar is replaced by a C major chord, based on the E and the G in the melody that are then the 3rd and the 5th of that chord.
And in the third bar, the last note Bb becomes part of a Bb major chord.


When you are harmonizing your melody, also keep in mind the rhythm with which the chords of your harmony change. That's called the harmonic rhythm.
And changing chords faster or slower can really change the feel of a song.

Here is an example of the same melody, harmonized with a lot more chord changes.


And just for some variety, here is a last example.


Now, just as we did, you can consider the notes of the melody like the root note, the 3rd or the 5th of the chords that support them. But they could also be the extensions of a chord, like a 7th or a 9th. 

For example, at the end of the first bar, we have a A and a F. And I liked the change from a D minor to a Bb major there. But the A was not part of the chord Bb major.
Yet, this is not a problem as this A can be considered as the major 7th in the Bb major chord. That would turn this Bb major chord into a Bb major 7th chord.


From the same principle, we could try to harmonize everything using extended chords like 7th and 9th chords. So that would open up a lot more possibilities.

In the first bar, if we put a Bb major 7th chord, the D become the 3rd of the chord, the A becomes the 7th and the F becomes the 5th

In the second bar we have a F major chord, with F, A and C. So in the melody, the E becomes the 7th and the G becomes the 9th, so the chord becomes a FM9.
Followed by a Dm7 chord. Because we have a D in the melody and it's good to lend on the Ist degree, but we can still keep the flavour of a 7th chord.

In the third bar we have D and a Bb, that I decided to consider like the 9th and the 7th of a 9th chord. And the chord I've built is a C#half-diminished 7th minor 9th chord, which is from the scale of D harmonic minor, with the C# (we saw that in the last episode about 9th chords)

And in the last bar, I turned the A dominant 7th chord we had before into a A dominant 7b9 by keeping this Bb from the previous chord.

Then I doubled some notes of the melody a 3rd below, by using notes that were already in the chord progression. I just liked how it sounded.


From there we can go even further by using non-diatonic chords. Chords that or not from the tonality we are in.
You can do that by borrowing a chord from another tonality or by substituting a chord for another one.

We saw several ways to do that in the episodes about borrowing and substitutions, for which I will also leave a link in the description.

But for the example I will focus on the secondary dominants only. 

A secondary dominant is when you take any chord in your progression, and for a moment you consider it like the Ist degree of its own tonality. So just before you can put the Vth degree of that chord to prepare it. So this chord you put before is in the tonality of the next chord, but not necessarily in the tonality of the rest of the song. that's the secondary dominant.

So here is how I harmonized this melody:
In the first bar we still have the notes D, F and A which are the notes of a Dm chord, so I've put a Dm7 chord for the flavour.

And in the third bar we have a D and a Bb, which I considered like the 3rd and the 5th of a Gm7 chord.

So to introduce a secondary dominant, we can consider this Gm as a Ist degree for a moment. So just before it I could put the Vth degree of the Gm scale, which is D major, or even D dominant 7. Which can work on this D in the melody.


There's also one way you could extend this secondary dominant. A secondary dominant utilises the tension of an authentic cadence, the tension of a Vth degree that wants to go back to its Ist degree.

And it's a common practice to prepare this authentic cadence by putting a chord of the IInd degree in front of that cadence. So the full authentic cadence would be II - V - I.
You can put the IInd degree of the chord you want to go to just before the V. That would make 2 chords that would not be necessarily in the tonality of the whole song. That's something that is used a lot in Jazz, for example.

Here for exemple, we could use a A° chord before the D7, because it would be the IInd degree of the Gm tonality.
Problem is the A diminished chord is made of the notes A, C and Eb, and we already have a E natural in the melody.
Because I didn't want to alter the original melody, I used a A dominant 7 chord instead, which is in the tonality of our song.


Then, to finish the chord progression, on this C#, I built a chord of C dominant 7b9, because I didn't consider that as a C# but as a Db.
So the C is the root note, E is the major 3rd, the 5th would be a G that is not there, the Bb is the minor 7th, and the Db in the melody is the minor 9th.
We saw this C7b9 chord in the episode about 9th chords, and it is again often used on a Vth degree to land on a Ist degree. So as C is the fifth of F, I've put a F major chord after, which utilises the notes from the melody that are on the down beats.

Then, just because I was in this kind of gimmick, I've put a BbM7 chord to begin the next loop, because F is the fifth of Bb. So the chord progression would go down a fifth from D to G, then down a fifth from G to C, then again from C to F, then from F to Bb. So it's like always going down in the circle of fifth.


We saw an example of non-diatonic chords with the secondary dominants, but you can also harmonise your melodies using all the chords, substitutions, borrowings and alterations we saw in the series. Just to name them we saw the parallel chords, the altered Vth chords, the tritone substitution, the napolitan 6th, the picardy 3rd, the faurean cadence, sus4 and sus2 chords or even the andalusian cadence.

I won't do an example for each of them now, as I think it would get very redondant at this point, and this video is already getting a lot longer than expected.
But I hope this video was clear enough or that it gave you some ideas for your next songs.

If you want to see more in detail how all these chords work, you can check out my playlist "music theory in 5 minutes", everything is in there.


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