Spice Up Your Chord Progressions With Non-Diatonic Chords.
- Yash
- Oct 7, 2022
- 5 min read
Updated: Jan 21, 2023
For every musician, a time comes when the typical sound of a major scale gets on their nerves. That is understandable because there is only so much you can do with just 7 chords and it gets boring. Today, I am going to give you a few tips to break out of this monotony by using non-diatonic chords.
A non-diatonic chord is any chord that has a note that doesn't belong to the scale in which the song is composed. For example, Fm is non-diatonic to a song written in the key of C Major, since its notes are F A♭ C, and A♭ doesn't belong to the scale.
Non-Diatonic chords can be used to spice up your chord progressions by stepping out of the scale and using notes that bring a fresh sound. Here are some commonly used ways of doing that.
Secondary Dominants
The function of a dominant chord is to create a pull toward the tonic chord. But that doesn't have to be limited to the V-I relationship in a scale. You can treat any chord in your diatonic progression as a temporary tonic and play its dominant (V7) chord before it, creating a moment of tension and release within the progression.
This is called a "secondary dominant".
In this article, I'll use this progression frequently to showcase various techniques: iii - V - ii - I. In the scale of C-Major, it would be
Em - G - Dm - C.
Now, think of Dm as a tonic chord for a moment. It's secondary dominant chord would be A7. (To learn more about Dominant 7th chords, you can read this article).
Now, you can modify the progression and play
Em - G - A7 - Dm - C.
Since Dm is the ii chord in the scale, A7 is written as V7/ii (Read V7 of 2).
You can do this with any diatonic chord; V7/iii, V7/IV, V7/V, V7/vi.
Passing Diminished
Passing diminished chords work in a very similar way to secondary dominants. We treat one of the diatonic chords in the progression as the I chord, and before it, we play a diminished chord built on a note that is half step lower than the target chord root. We can use a half diminished 7th or full diminished 7th chord too.
You can learn more in depth about passing diminished chords by reading this post on all sorts of diminished chords.
In our example, we could use a passing diminished before the G chord, giving us:
Em - F♯° - G - Dm - C
The diminished chord is generally kept very short because it is unstable, and if sustained, it disrupts the flow of harmony.
In this case, passing diminished is written as vii°/V (Read vii° of V, since the target chord is V)
Tritone Substitution
Tritone substitution is a very useful way to create chromatic movement between chords, and a proper explanation of it is out of scope of this post, but you can read all about it here.
Essentially it is a Dom7 chord built on a note that is half step higher than the target chord root.
For example, in the previous progression (Em- G - Dm - C), between Dm and C, we can use C♯7. Here the target chord is C, so we go half step above it to C♯ and play a dominant chord on that root. This creates a nice chromatic movement of the root note from D to C♯ to C.
The progression becomes:
Em - G - Dm - C♯7 - C
Modal Interchange
Modal interchange is one of my favorite ways of adding some spice to a song. At any point in the progression, you can borrow a chord from a parallel mode and add it to the progression (or replace an existing chord with a borrowed chord.
If you are not familiar with the concept of modes, I have written a 3-part article starting here.
2-5 Progression.
Who doesn't love a 2 for 1 combo? That's what you get when you use this technique. Like everything else on this list, you treat the target chord as the tonic temporarily, and then play the famous ii-V-I progression leading up to it.
I'll use a new example for this:
C - F - Dm - G - C.
If the target chord is F Major, imagine that is the ! chord. That will give us Gm as the ii chord relative to it, and a C7 chord as the V7 chord relative to it. Thus we can make the progression into this:
C - Gm - C7 - F - Dm - G - C.
This would be notated as ii_V7/V, since the target chord is V, and we are playing ii and V7 relative to that before it.
In case of minor target chords, you can use ii°_V7. For example, let's reuse our original progression progression: Em - G - Dm - C
Targeting the Dm chord with a ii°_V7, we can get:
Em - G - E° - A7 - Dm - C
Augmented Triads
Augmented chords often go unnoticed because they are not as versatile as diminished chords, but they are a good way to introduce some chromatic movement in your progressions.
Example: If you are trying to go from C Major to A minor, you can play C Augmented chord in between. The notes in this progression would look something like this:
C Major | C | E | G |
C Augmented | C | E | G♯ |
A Minor (1st Inversion) | C | E | A |
Here the top note is moving by half steps from G to G♯ to A.
If you want the chromatic movement at the bottom of a chord, here is an example of that:
Cm - B Aug - E♭
C Minor | C | E♭ | G |
B Augmented | B | D♯ (E♭) | F♯♯ (G) |
E♭ (2nd Inversion) | B♭ | E♭ | G |
There are other possibilities as well that you can explore.
Augmented Dominant 7th (Aug7)
An augmented dominant 7th chord is made up of 1 - 3 - ♯5 - ♭7 intervals. You can use it instead of the dominant 7th chords in all the previous examples where we were using secondary dominants or tritone substitutions.
Here is the first example I used with secondary dominants:
Now I am using an Aug7 chord, which is significantly more dissonant, giving us a temporary feeling of dread in an otherwise calming progression.
Mixing Minor Scales
So far we have been looking at only major scale, but minor scale has a unique feature. It comes with melodic minor and harmonic minor scales. So if you are writing a progression in a minor key, you can borrow a chord from a the harmonic or melodic minor scales built on the same note. All three of them are a part of the package.
You can check out my article on Harmonic Minor to get an idea of how that scale works.
A full explanation of this topic would be covered in a future post, so please subscribe to get notified about it in your mail!
I found an interesting thread at music stackexchange discussing this method. Do check it out if you like browsing forums.
Other Sources
The methods I mentioned are just some of the common ones used, but this is limitless topic since there is a vast variety of chords that are possible.
Check out some of these sources to get more ideas on using non-diatonic chords:
HackMusicTheory uses an approach to choose chords based on a common note.
Bill Hilton explains how to use non-diatonic chords without sounding too jazzy.
Conclusion
Hope some of these ideas prove useful to you while composing your own music.
What methods do you use to break out of the diatonic box? Share your ideas and opinions in the comments.
Thank you for reading! Please share this blog if you found the information to be interesting. Check out my other posts for more tips and explanations of various concepts.
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