A borrowed chord is a chord that is ‘borrowed’ from the parallel key. Meaning, if we are composing a song in C major, then we would borrow chords from C minor. There’s a few rules you can follow as you learn.

For example:

Below are the three common minor scales and their accompanying chords;

Key:

m = Minor, M = Major, o = Diminished, + = Augmented

Natural

A B C D E F G
m o M m m M M

Melodic

A B C D E F# G#
m M + M M o o

Harmonic

A B C D E F G#
m o + m M M o

It should be noted that the most common borrowed chords from the minor key are:

ii - The diminished chord

iv - The minor chord

bvi - The major chord

This does not mean that you shouldn’t try other combinations like incorporating the augmented chord on the III of the harmonic minor scale or the two diminished chords at VI and VII of the melodic minor.

Food for thought: Borrowing chords can lead to an easier and smoother way to modulate to a different key.