In this article we're going to dive into more detail on how melodies can be created from chord progressions, as well as take a look at different ways of harmonising a melody.
Let’s say we have the following chord progression: Dm - G - C. In order to write a melody from this progression we first need to decompose each chord into its constituent notes. So for this progression we would have (DFA) - (GBD) - (CEG). Each one of these groups of notes contains the harmonic notes available to us while that particular chord is taking place. The other four notes of the scale will be the non-harmonic notes. A typical way to organize these two categories of notes, and one you can’t go wrong with, is to place the harmonic notes on the downbeats and the non-harmonic notes on the upbeats. Something like this:
NON-HARMONIC NOTE TYPES
Going a bit more in-depth into melody theory, we can distinguish between several types of non-harmonic notes depending on whether they are accented or unaccented, on whether they move by step (interval of second), by skip (intervals bigger than a second), or by stay (not moving).
For unaccented notes we have the passing tone, which is a dissonance approached and resolved by step in the same direction, neighbouring tone, which is a dissonance approached and resolved by step that occurs between two instances of the same harmonic note, anticipation, which is a dissonance approached by step taken from a note of a subsequent chord and resolved by stay, and escape tone, which is a dissonance approached by step and resolved by skip in the opposite direction.
As for accented non-harmonic notes, we have the appoggiatura, which is a dissonance approached by skip and resolved by step in the opposite direction, suspension, which is a dissonance sustained from a previous harmonic note and resolved by step downwards, and retardation, which is a dissonance sustained from a previous harmonic note and resolved by step upwards.
Now we can mix and experiment with all these techniques whenever we set to write melodies on top of chord progressions. But what if we have a melody we want to harmonize or write a chord progression on top of? That’s what we’re going to look at next.
Say we have this melody:
The first thing we need to do is to look for intervals of third between the notes of each measure.
These intervals are going to narrow down the list of possible chords to only two: the one whose root coincides with the root of each interval, and its parallel chord. If you don’t recall what parallel chords are, check the part 3 of this series for a refresh.
In the first measure, the two possible chords are F and Dm, in the second measure G and Em, and in the third measure, C and Am. If the notes of a particular measure also include a fifth from the root of the third, we can also rule out the parallel chord. Conversely, if the notes of a particular measure also include a sixth from the root of the third, we can know for certain that the parallel chord is the most suitable option. If it includes both a fifth and a sixth or none of them, like in our case, we can pick any of the two.
In cases where we can’t find intervals of third per measure, we can either try to find them across several measures and use chords longer than one measure or simply use a trial and error approach and try out the seven different chords of the key on each measure and see what sounds best.
Once we have a suitable chord progression for our melody, we can use different harmonization techniques to harmonize the melody. One of the most common of these techniques is the use of stacked chords. For this technique, we simply accompany the melody with chord stacks like so:
Chord stacks are very versatile depending on the type of sound we apply them to. They can be very powerful with short attack instruments as well as extremely soothing and mellow with sustained ensembles and long attack instruments.
The chords can have their own independent rhythm and can be repeated in different inversions and with different extensions in order to add excitement and complexity to the harmony.
Another common harmonization technique is the arpeggio, which is based on repeated patterns of juxtaposed chord notes. Arpeggios work on the premise of disposing the notes of chords horizontally and playing them one at a time. As with stacked chords, the arpeggiated chords can be inverted and extended with embellishing non-harmonic notes in order to make them more interesting.
Arpeggios can be very expressive and emotionally driving, and given their horizontal quality, they are open to a higher degree of melodical variability, agility and speed.
The last harmonization technique that we’re going to examine is the most ancient of all, to the point of being largely considered as a precursor of harmony rather than an actual harmonization technique. I’m talking about counterpoint, which is a way of harmonizing a lead melody with other secondary melody or melodies. This technique can be kept very simple by employing secondary melodies that simply mirror the lead melody at different intervals like this:
Going further in complexity, the rhythm of the secondary melody can be modified to the point of giving place to completely new melodies, totally different from the lead melody, not only in terms of the notes, but also in their position, duration and amount. Here’s an example:
These three harmonization techniques can be used by different instruments in our arrangements as well as combined into a single MIDI part. Traditionally, melodic instruments such as strings and winds have been in charge of counterpoint and arpeggios, whereas chord stacks have been delegated to orchestral and big band ensembles. In more modern and recent setups, polyphonic instruments like keyboards, guitars and more recently synthesizers have been able to alternate smoothly between these three techniques.
That’s all for this article on basic melody creation and harmonization theory. In it, we have taken a look at how to write melodies based on chord progressions as well as different ways of working out chord progressions from melodies. We’ve also explored three different harmonization techniques that can be combined into more advanced and complex musical parts.