Tired of using the same old chords in your cues? Modal interchange (also called borrowed chords) is a great technique to add variety and interest into your chord progressions. It’s an idea borrowed from jazz, but I guarantee you’ve heard it in hundreds of pop songs and film scores as well. You’ve probably even used it yourself without realizing it.
Modal interchange combines two rather simple principles. The first is the harmonized major scale. Simply put, that’s a fancy name for taking the notes of the major scale and building triads or sevenths on top of each one using notes diatonic to the scale. In C major, you end up with CMaj7, Dmin7, Emin7, FMaj7, G7, Amin7, and Bmin7b5.
The other principle at work in modal interchange is, as you might guess, modes. Modes have a long history, but in modern use you create a mode by taking the notes of the major scale and beginning on a different scale degree to get at a new arrangement of intervals. In our C major example above, starting on D and using the same white-key notes gives you the Dorian scale (a minor scale with a raised sixth). The rest of the modes are:
- Phrygian: minor scale with a flat 2
- Lydian: major scale with a raised 4
- Mixolydian: major scale with a flat 7
- Aeolian: plain old minor scale
- Locrian: minor scale with flat 2 and flat 5
All the modes use the same notes as the C major scale, but with a unique arrangement of intervals and a unique sound.
Just like the major scale, you can build chords on top of the notes of a modal scale as well. A harmonized D Dorian scale would be Dmin7, Emin7, FMaj7, G7, Amin7, Bmin7b5, Cmaj7.
The final step for finding modal interchange chords is to transpose all our modal scales back to the key you’re in. So the harmonized Dorian scale above would become Cmin7, Dmin7, Ebmaj7, F7, Gmin7, Amin7b5, Bbmaj7. This gives us some unique chords we haven’t seen yet in the key of C: Gmin7, EbMaj7, Bbmaj7, F7. Now, here’s the cool part—we can take these new chords and use them with our plain vanilla C major chords to create interesting new harmonies. And since all the chords are borrowed from a parallel C scale, they sound exotic but still fit with our C major chords. Listen to the following progression, which uses the bIII and bVII:
Of course, you can do this with all the modes, and freely use chords from any modal C scale. This gives you numerous new chord possibilities. Some of my favorites are: bIII, IVm, Vm, bVII, bVI, IIMaj, and IIm7b5.
Some of these are sure to sound familiar. The bVII is common in rock songs, for example. Here’s a Clash song that uses both the bVII and the bIII:
And here’s a song from The Little Ones that starts on the always interesting IIm7b5:
Yes, these are pop songs, but modal interchange is right at home in film scores too. In the love theme from Superman, the Movie, John Williams uses a II Maj chord to harmonize the theme (at 1:17).
Since the II Maj chord is borrowed from the Lydian mode, it gives the theme a hopeful, swelling feeling, perfect for a romantic cue. (Williams also uses a bVI chord later in the progression, but this isn’t actually a modal interchange chord. It’s technically a tritone substitution for the II chord. More on that in a later post.)
Play around with chords from different modes and try them out in your pieces. I guarantee it will open up a whole new world of harmonic possibilities.