>Step by step
Harmonising your melody
1 Let’s start by assuming you have a melody in your head that you’ve successfully transcribed into your DAW’s piano roll. Here’s an example that I’ve come up with for the purpose of this tutorial. Our first job is to try and work out the key, so let’s start by examining the notes in the melody.
2 If I select each melody note in the piano roll editor from the lowest note upwards, my DAW tells me in the vertical keyboard display which notes I’m selecting. In this case, the notes in the melody all seem to be white notes, except for the third note from the bottom, the Bb. very last note, which is a
3 Since Bb is the only sharp or flat note used, it’s safe to assume the melody might be in the key of F major, as F major Bb. is a scale that contains one flat – All other notes used in our melody also occur in the F major scale, the seven notes F, G, Bb,
A, C, D and E (the eighth note is a repeat of the F root note, an octave higher).
4 The only other possible key might be F major’s relative minor key of D minor, since this shares the same notes as F major and therefore also only contains a
Bb. single flat, However, we can rule out the likelihood of a minor key simply because of the melody’s upbeat, cheerful tone, which definitely suggests a major rather than minor quality.
5 The parent scale of a key is the one that shares its name. So if we suspect the song’s key is F major, then the parent scale will be the F major scale. To get the diatonic chords for the key, we need to harmonise the parent scale. This is done by going through the notes or degrees in the scale and stacking up every other note to make three-note chords or ‘triads’.
6 Now that we have the diatonic chords, we can label them using Roman numerals, based on the position of each chord sequentially within the scale. We use uppercase numerals to denote major chords, and lowercase for minor and diminished chords (there’s always one diminished chord – the vii chord – in a harmonised major scale).
7 The benefit of using the Roman numeral system to label diatonic chords is that you can spell out a progression and it’ll translate to every conceivable key. Once you know what the I chord is – it’ll have the tonic of the parent scale as its root note – you can then work out the relative positions of all the other chords that are diatonic to that key.
8 So for example, a IV-I-V-vi progression Bb- in F major works out as F-C-Dm, because the IVchord in the key of F major
Bb is major, the I chord is F major, the V chord is C major and the vi chord is Dm. However, in the key of C major, the same progression would go F-C-G-Am as the IV chord in the key of C major is F major, the I chord is C major, and so on.
9 So now that we have the diatonic chords all identified and labelled up, we can try to find a progression that might fit our melody notes. The most commonly-used chords in any key are the primary chords, namely the I, IV and V chords, so how about starting with just a I-IV-IV-V Bb-progression? This would work out as F- Bb- C in this key.
10 That works okay, the top notes in the chords match up nicely to the melody notes, so we’re on track. We could vary things a little though by slipping in a subtle ii chord – a Gm chord – as the third chord in the progression to balance things out and give us a nice, rounded four-chord I-IV-ii-V progression.
11 Once we’ve got a progression that works, we’ve essentially got the chords to this part of our song, so we’re free to alter the rhythm and sound to create a complementary part to the melody. I’ve stuck with I-IV-ii-V and used a choppy, rhythmic synth part courtesy of Dune CM’s 055 Marimba RH preset.
12 To smooth out the chord changes, I’ve used inverted versions of the chords, with the notes stacked in different order from bottom to top. To finish things off, I’ve added drums and a bass part based on the root notes of the chords but which also uses chord tones from the parent F major scale.