music theory

Songwriting and a quick lesson in music theory

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Music theory won’t dictate the correct chord progression or choices for your song; that’s what your ears are for! Instead, it’s there to help you with chord choices, melody decisions, ways to build vocal harmonies, and more.

music theory
Has this ever happened to you? You’re writing a song and you’re off to a good start. You’ve hit on a vocal melody you like and you’ve got a few chords, but you just can’t seem to finish the chord progression. You keep trying all the chords you know, but nothing seems to fit. After some frustration and failures, you put the idea aside, forget all about it, and another song bites the dust.

What a waste! How many songs of yours die half finished because of this? The solution might be just learning a bit of music theory. It can make finding those last few chord a heck of a lot easier, it can certainly open up a list of new possibilities.

Now let’s pause for a moment: music theory sometimes gets a bad rap, perhaps because it’s not taught that well, is misunderstood, or is just plain intimidating. If you believe music theory is: A) for classical musicians only, B) exclusively for passing boring exams, or C) the enemy of creativity, then you have the wrong idea. Let’s fix that. Music theory is helpful and is a valuable tool for any songwriter, and I’ll show you what it can do right now.

Let’s write a song

Here’s a melody I came up with for guitar. Super simple, right?


Next step is to add some chords. Let’s say I started working off the top of my head and randomly chose chords to see what might fit. This could take a long while, and maybe I’d end up with something like this:

Melody and Chords version 1

Those chords don’t sound quite right, do they? Now let’s try a music theory approach. Before we get started, there are a couple terms we should cover:

  • Key. A key is essentially just a group of notes (usually seven) that work and sound good together. Sometimes an entire song will only use notes from a single key, but not always. Sometimes a verse will be in one key and a chorus in another, and other times the key can change constantly! Note: “Scale” is often used interchangeably with “key,” but scale generally refers to all the notes in a key played in ascending or descending order.
  • Chord progression. A chord progression is several chords played, one after the other (A minor, C major, B diminished, E minor, for example). Songs generally involve both a melody and a chord progression for each section.

Choosing your chords

1. Find the key. The notes in our melody are as simple as it gets, just C and D. As we now know, a key in music is a set of notes that sound good together. If we can find a key that includes C and D, we’ll then have another five notes we could play with this melody, not to mention a bunch of chords that will fit, too.

For our melody, there are a few keys that could work, but we’re going to pick the most obvious: C major. (Play around with Ten Kettles’ KeyFinder to find others.) The key of C major has seven notes, and here they are:


2. Find the chords. Once you know your key, there’s a simple formula you can use to find seven chords that will fit well. Bear in mind, this isn’t a cut-and-dry process; sometimes the most rewarding musical choice is the least expected. That said, nine times out of ten, you’ll find the chords you want by applying this formula. Line up the notes in the key (i.e., build the scale), and the corresponding chords will be “M m m M M m d,” where M is major, m is minor, and d is diminished.

Here’s what you get for the key of C:
C major
D minor
E minor
F major
G major
A minor
B diminished

3. Build a chord progression. A chord progression is simply a series of chords you play, one after the other. You can start the progression with the first chord (that’s C major) because it’s the most important one of the key, then follow your ear for the rest. There are only six other chords, experimenting with the available options won’t take long. There are bound to be obvious progressions which sound good (which is why some chord progressions are used repeatedly – check out the video below), but this comes down to musical choice, the mood you’re trying to achieve, and how experimental you want to be.

Ultimately, all that matters is, what do you like the sound of? Personally, I think the progression “C major, F major” works well with the melody. Here’s what that sounds like (each chord is played twice):

Melody and Chords version 2

Keep learning

Sounds pretty good, right? There are plenty of other ways to match chords and melodies, but this is applied music theory, and it works well. Music theory is a toolbox, and understanding it will aid you in understanding why certain chords and melodies work. Music theory won’t dictate what is the correct progression or choice for your song; that’s what your ears are for! Instead, it’s there to help you with chord choices, melody decisions, ways to build vocal harmonies, and more.

Alex Andrews is an engineer (B.Sc. Engineering Physics, M.Sc. Electrical Engineering) and musician who runs an indie app company called Ten Kettles. Based in Toronto, Canada, Ten Kettles builds apps for music education from the ground up. Their newest app, “Waay: Music theory that matters,” brings together video lessons, interactive exercises, and progress-tracking tools to teach music theory for songwriters.

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