Borrowed chords
Recognise chords borrowed from the parallel key (modal interchange).
A song in a major key sometimes uses a chord that is not in the major scale at all. It is not a mistake: it is borrowed from the parallel minor.
Modal interchange
Modal interchange (borrowing) means using, in a major key, chords from its parallel minor (lesson 6.3) or from other parallel modes, or the reverse. A chord taken this way is a borrowed chord. The most common borrowings in a major key come from the parallel minor (C major borrowing from C minor):
| Numeral | In C | Typical use |
|---|---|---|
| iv | Fm | IV → iv → I, a softer, sadder return home |
| ♭VI | A♭ | ♭VI → ♭VII → I, a “rock” approach to the tonic |
| ♭VII | B♭ | ♭VII → I, or as a substitute for IV or V |
| ♭III | E♭ | colour, often with ♭VII |
| ii° / iiø7 | D° / Dø7 | before V, darker than ii |
| Key | iv | ♭VI | ♭VII | ♭III | ii° |
|---|---|---|---|---|---|
| C | Fm | A♭ | B♭ | E♭ | D° |
| G | Cm | E♭ | F | B♭ | A° |
| D | Gm | B♭ | C | F | E° |
| F | B♭m | D♭ | E♭ | A♭ | G° |
The ♭VII, the flat seven chord, is the most frequent borrowed chord in rock and pop. It is also the chord of the Mixolydian mode (lesson 13.5). Unlike V and vii°, it has no leading tone, so its pull toward I is softer. It often moves to IV or to I.
In a minor key the borrowing goes the other way: the major V is so common that it counts as standard (lesson 8.3); the major IV gives a Dorian colour; and a major I at the very end of a minor piece is a traditional effect, the Picardy third.
For the bass
Borrowed chords often create chromatic or stepwise bass motion. ♭VI → ♭VII → I is A♭ → B♭ → C, rising by whole steps. IV → iv keeps the same root (F → F) while the 3rd changes, so the bass can stay put while the colour changes above it. Borrowed chords use the flats of the parallel minor: ♭VI in C is A♭, not G♯.
Play roots of C–F–Fm–C (stay on F for two bars while the chord changes), then C–A♭–B♭–C. Describe the colour each borrowed chord adds.