By Matthew Chanway
This article is targeted towards intermediate level players who have some experience with songwriting, and specifically writing chord progressions. If you've been a student of mine or any reputable teacher, likely you've learned about the diatonic chord formula for major and minor keys – in other words, being familar with the 'I' chord being major in a major key, the 'ii' chord being minor, such and so forth. When you first learn this formula, it can be quite liberating as it can show how a lot of really popular songs use chord progressions derived from it. So much of the magic in songs we know and love come from selecting a few numbers, and then playing those chords on a guitar.
If you're strictly interested in composing pop music, you may find that the original diatonic chord formula may be enough for your songwriting purposes. However, for most other styles, and even in certain sub-genres of pop music, you may want more chords to play with, and that is what we will explore today.
Let's say we begin writing a song in the key of C Major. The seven chords of C Major are Cmaj7, Dmin7, Emin7, Fmaj7, G7, Amin7 and Bmin7b5. Here are three approaches we could take to expand our available chords to work with:
Option 1: Modulate To Another Key Using The Circle of 5ths
This article assumes you are aware of the circle of 5ths and what it represents. The key signature next to C Major is G Major. You're likely aware already that adjacent keys on the circle of 5ths have only a one note difference in their key signature. So, the notes of G Major are G, A, B, C, D, E, F# - only F# is different from C Major. However, if we carry out our diatonic formula in G Major, we end up with the chords Gmaj7, Amin7, Bmin7, Cmaj7, D7, Emin7, F#min7b5. Even if we ignore the min7b5, we still have three new chord possibilities – Gmaj7, D7, and Bmin7. These chords may work well to complement your existing chord choices in C Major.
Option 2: Modulate To The Key Of Any Chord in C Major
Another possible smooth transition would be to modulate to the key signature of any diatonic chord in C Major, for example, modulating to F Major. This would yield us the chords Fmaj7, Gmin7, Amin7, Bbmaj7, C7, Dmin7, Emin7b5. Lots of potentially interesting chords come up from using this technique. We would generally avoid the vii or min7b5 chord when picking a key to modulate to.
Option 3: Modulate To The Parallel Minor Key of C Major
A parallel minor key is the minor key of the same root note as your original major key. For example, C Minor is the parallel minor key of C Major. If we take this approach, remember that the diatonic chord formula for minor keys is the same as major keys, we can just consider it as starting on the 'vi' chord of the major key. There are a couple of steps here, but the chords of C Minor will be Cmin7/Dmin7b5/Ebmaj7/Fmin7/Gmin7/Abmaj7/Bb7.
Regardless of the approach you chose to adopt, make sure you have a strategy in place of how you plan to shift between keys. Do you want to just borrow one chord from one of these other keys? Or, do you want to do one or two chords from your original key, and then modulate to your new key for the rest of
the progression? There are many possibilities, but by expanding your chord awareness, you can ensure that you are never stuck for effective chords to use in your songwriting process.
Matt Chanway is a professional guitarist and teaches guitar lessons in Surrey, British Columbia.