Quick note before reading: you’ll find this article most helpful if you practice the ideas here with a melody you’ve already written. If you want to do that as you read (highly recommended), check out our How to Write a Melody Quickly article so you have everything you need to get started!

Types of harmony and its purpose

Most of the time, you’ll be writing what’s called ‘diatonic harmony.’ This basically means that all the notes in the chords are part of the same master scale. Nothing fancy. Non-diatonic harmony, on the other hand, uses notes not in the scale — often this is for the purposes of functional harmony to add more pull or a stronger chord progression. For example, the progression D7 – G7 – Cmaj — the F# in D7 definitely isn’t in the C major scale, but it creates a stronger pull toward the G7, which you might want. That’s up to your musical taste!

The main purpose of harmony is twofold: to create chords, and to support the melody (there are others, but we’ll keep it simple here). If you want to dive more into chords, you can check out our article on How To Create a Chord Progression — that should help answer a lot of your questions. Supporting the melody is more complex, though; you know the melody and the chords, but of course songs are more complex than that. What rules should you follow? How do you develop a natural instinct for what sounds good and what doesn’t?

Let’s dive deeper into how to use harmony outside of just plunking out a few chords and throwing melody on top — starting with the basics.

How to write harmonies

The first thing you want to ask yourself is: “What notes are in the chord, and what’s already taken by the melody?” This is often the fastest way to get to a working harmony — double up some of the notes already in the chords and move with the melody. The key here is movement; if the harmony isn’t moving with the melody, then it’s just part of the chord!

When you’re not sure where to start, try transposing the melody down by a set interval (a third and a sixth often work well). You’ll need to adjust a couple notes here and there to keep everything diatonic, and you’ll know immediately when you don’t because a ‘wrong’ note will jump out at you. Sometimes this is enough — you can set it and forget it, using a different instrument to play the harmony line and usually at a lower volume.

This will eventually become limiting, however. The best harmonies are sometimes a fourth away from the melody, others a third, then a sixth, etc. A great guideline to follow if you’re not sure whether it’s good: make sure it sounds right when played together with the melody. Then solo the harmony line. If it still sounds good, then great! You can happily leave it alone. If only one of those two is true, make adjustments until the harmony sounds good both with the melody and on its own.

But this too will become restrictive at some point. There will come a time when you’re tempted to follow the melody sometimes and do something different during others. This is where counterpoint comes in!

A quick guide to writing effective counterpoint

To keep things straightforward, think of counterpoint as a second melody that plays at the same time. If your music doesn’t sound finished and you’ve already added in a melody, chords, harmony, rhythm, etc., you might be skimping on countermelodies. Try writing a second melody that doesn’t clash with the main melody and see if you can get them working together. A good countermelody frequently harmonizes with the melody, but it should feel spontaneous. If it has the same rhythm as the melody, it’s simply a harmony line.

This keeps things interesting and fills out space in the mix when it feels like something is missing. A great hack is to write a strong countermelody and bring the volume level super low in the mix, so low that it almost doesn’t feel like it’s there. Most listeners won’t even know you did this, but the song will mysteriously be more satisfying to listen to because you gave it something extra.

Three-part harmony

There’s nothing saying that harmonies can only be a single note! One of the most prominent examples of this is in gospel music — vocal harmonies are often in threes, and they don’t always stick to the underlying chords.

Say you’re in the key of D major and the current chord is a Dmaj. Part of the melody is D – E- F#; the harmony lines could be A – B – D and F# – G – A and move together with the melody. B and G aren’t in the chord, and are referred to as ‘passing tones’ — so three-part harmony doesn’t necessarily mean you’re simply playing the chords. Yes, adding more notes can make things cluttered very quickly, but as long as you take your cues from everything else that’s going on in the song, with practice you’ll learn when your songs could use three-part harmony (or even four-part) vs. when it’s simply too much to use more than a single melody and harmony line (two-part harmony).

Another important point: when stacking harmonies to three or more voices, don’t use the same harmony structure throughout the entire song. Have some parts with two-part harmony and plenty with no harmony at all. There are no rules for what type of harmony to use and when, but when in doubt, refer back to songs you like and take inspiration from those. Chances are that someone’s already created a sound similar to what you want to achieve, which is why it’s always a good idea to listen to as many songs as possible in widely varied genres.

What instruments to use when creating harmonies

Good general rule to write better harmonies faster: use the same or a similar instrument to whatever is playing the melody. Otherwise, you’ll end up fighting two battles at the same time: whether the harmony is good, and whether you picked the best instrument to play it. You can always change the instrument later, so eliminate that for now.

Once you have the harmony written, feel free to experiment with no restrictions! But if you’re looking for a guide to get you started, here are a few things to try:

If the melody is played by an acoustic instrument and the overall arrangement is light and gentle, try using an acoustic guitar for the harmony line. If you’re feeling adventurous, you can even have it play the harmony and double the melody at the same time! Virtual Guitarist AMBER is a great VST plugin to get you started — you can create harmonies, melodies, and even chords quickly and simply keep the parts you like. Its tone is soft and forgiving, making it a great option to test whenever you’re in doubt. Mixing the combination of two different instruments can be especially tricky with guitars; if you really want to lock the harmony into your mix, give our How to Mix Guitars article a read to give it some extra polish.

Acoustic and electric pianos are great for harmonizing — and since they’re chordal instruments, you have more flexibility to switch between chords and harmony on a whim. There’s no reason the chords and harmony line can’t be played by the same instrument! If you’re looking for versatile piano VST plugins, there are tons — but it’s hard to go wrong with Native Instruments’ The Maverick (great all-around timbre) and Cinesamples’ Piano in Blue (for a more stylized or vintage feel; excellent solo instrument).

If you’re using a synth, duplicate the instrument track and make tweaks to the original patch or preset. That way you get the benefit of a similar timbre while still freely creating a different sound as you see fit. Because synths are so flexible, for electronic music this is typically your best bet.

Bringing it all together

Harmony isn’t as simple as using whatever is in the chords — it has its own place in each song, and the way you use it can make the difference between an okay song and a highly memorable one. Every song needs a slightly different approach to harmony, and this article should give you a strong starting point whenever you feel stuck. Have fun, and don’t feel guilty about starting with the easiest approach first — the most valuable thing you can focus on is speed, because you’ll finish songs faster and give yourself more opportunities to practice creating harmony.

There are no ‘rules’ for what makes good harmony; it’s helpful to know classical theory (which sets very clear rules), but music is evolving all the time. The only true rule is that you should do whatever sounds the best! Listen to different songs and see how they approach harmony differently — when you can, create harmony that’s not common practice in your genre. Take inspiration from other sources and experiment. That’s the only way to build a recognizable sound … and in the end, isn’t that part of the goal?