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Music Theory For Songwriters

learn music theory music theory Sep 04, 2021

How much music theory do you really need to know to write songs?

Do you need to know every bit of music theory your music major friends know? Do you need nothing?

I think there are 3 necessary bits of music theory you need to write songs. The more you learn, the better equipped you are, but these 3 are enough.



You need to know what people mean when they say “this song is in the key of E Major”.

Keys are like a rule set. Trying to write a song with no knowledge of keys is like those 4-year-olds playing soccer. They pick up the ball, they go out of bounds, and they shoot at the wrong net.

They can’t even begin to really learn strategy yet, because they don’t even understand how the game is played!

Once you understand keys, you have the groundwork for all the rest of music theory.

The rules of the key you’re in tell you every note you have to work with. No more wondering “would this note sound good with this song?” or “why does this melody just sound wrong?”.

You’ll know that playing a C in the key of A major is going to probably sound terrible. Because C is NOT in the key of A major. But it is in the keys of A minor, C major, G major, Bb major and more.

You’ll know that if your song is in the key of E major, the notes you have to work with are E, F#, G#, A, B, C# and D#.

Keys give you the ruleset you’re working with.

Once you learn keys, it will help you to understand the next important music theory concept.



A song is basically 3 things: Lyrics, Melody, and Chords.

The chords are the foundation of everything that happens on top of them. The chords influence the melody and the entire song arrangement.

You might often say “My bad” as a substitute for “I’m sorry”.

This works fine until you say it at your mother-in-law’s funeral. Then you get arrested.

And that’s exactly what you’re doing when you say stuff like “C Major is a happy chord!”

No. How C Major sounds in music is completely dependent on context.

In the key of C Major it will sound like home. It will sound powerful.

In the key of B Major, it will sound terrible. Nothing happy about what just happened. Just bleeding eyes and ears that shrivel up to make this travesty stop.

Don’t tell me C Major sounds “happy” or is a “happy chord”. Context is everything and C Major is NOT enough information to determine how it sounds. In context of the key, what chord is it?

This is where roman numeral notation comes in.

Roman numeral notation defines chords within the context of keys.

For example, let’s use the key of C to keep things simple.

The key of C includes the notes C, D, E, F, G, A, B

Also, all major keys have a Major I chord, minor ii, minor iii, Major IV, Major V, minor vi, and diminished vii.

So, for the key of C Major, we have a C Major (I), D minor (ii), E minor (iii), F Major (IV), G Major (V), A minor (vi), and B diminished (vii)

For the key of B Major, we have a B Major (I), C# minor (ii), D# minor (iii), E Major (IV), F# Major (V), G# minor (vi), and A# diminished (vii).

Let’s go back to that C Major “happy” chord in the key of B Major. A C major chord is C, E and G. C and G are supposed to be sharp in the key of B Major. So ⅔ of the notes in “Happy C Major” chord don’t even belong in the key.

Your precious happy C Major chord is more ugly than the Hunchback of Notre Dame in B Major. MUCH more ugly.

The ugly duckling sent your C Major chord a sympathy chord it’s so ugly.

This is why it is so important to learn roman numeral notation- chords within the context of keys.

An important thing to understand about this roman numeral notation is that each of these roman numerals have a specific sound. G Major in the key of C and F# Major in the key of B sound the same, because they are both V chords. They both have the same job.

So it’s important to understand the job of each of these chords.

It’s good to know what an A Major Chord is. But what you really need is to understand the chords within your key. What is the job of the I chord? How about the vi? These are the questions you need to be able to answer.


Chord Progressions

Remember how I just explained how context is everything to a chord? That isn’t just true for context within a key.

The context within a song is vital as well. Even though a I and ii chord are both valid chords in your Major key song, that doesn’t necessarily mean that a chord progression of I – ii – I – ii will sound good.

In fact, it probably won’t.

I, IV, V and vi are going to be your main chords.

I sounds like home and will be the most powerful.

IV and V are your other major chords. They also have a strong feel, with V longing to return to I.

And vi seems to be the only minor chord any pop song will ever use.

If you listen to pop radio, those 4 chords are probably the only 4 you hear. They are convenient, because you can go from any of them to any other one and it will sound fine. Once you involve ii and iii, it starts to become a lot more interesting.

Understanding chord progressions (flow of one chord to the next) is a huge bonus to songwriting. This allows you to play with the listeners’ emotions. You can give feelings of resolve, suspense, shock and so much more. And all of this can be done with chord progressions. They didn’t see that iii chord coming, did they!

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