30. Modal Interchange

Popular songs commonly use diatonic chord progressions, and it is good to have a working knowledge of diatonic harmony as a foundation for figuring out chord progressions, training the ear, and writing and analyzing complete tunes. Of course, not all songs use diatonic progressions only.  Modal interchange refers to the set of chords derived from the parallel minor. In other words, the minor key that starts on the same note as the major key.

Example: C minor is the parallel minor of C major, G minor is the parallel minor of G major, etc.

This is different than the relative minor, which is derived from the sixth degree of the major scale.

Example: A minor is the relative minor of C major, and E minor is the relative minor of G major.

As you have seen, the relative major and minor relationship means the same notes, the same chords, but starting at a different place in the scale.

The parallel minor to any key gives another set of chords, and these are the most common chords to look to first when analyzing a song that has non-diatonic chords. Below is a sample key, and the chords derived from both the major and parallel minor.

Sample Key: A Major

A Major                                                 A minor


(I )    A major                                           (i) a minor

(ii)     b minor                                          (ii) b diminished

(iii)    c# minor                                       (III) C major

(IV)   D major                                          (iv) d minor

(V)    E major                                           (v) e minor

(vi)   f# minor                                         (VI) F major

(vii)  g# diminished                             (VII) G major


To more easily see the relationship of the parallel minor, think of it as its relative major, starting on the 6th degree. Therefore, A minor, which is the relative minor of C major, is really this:


(vi) A minor

(vii) b diminished

(I) C major

(ii) d minor

(iii) e minor

(IV) F major

(V) G major

Comparing the diatonic chords of A minor to C major, we see they are the same, as with every relative major/minor. However, comparing the parallel minor to its major now shows 7 additional chords (6 if we don’t count the vii diminished). On the following page are some famous song examples which use parallel minor chords. Further study reveals that many chords have one or two tones in common with others, and chord substitutions are derived from these. For now, these two chord groups provide a great start.


In the same way I suggest looking to the diatonic chords in a key FIRST when trying to learn a song’s progression, always look NEXT to the parallel minor.  Most popular songs will derive all of its chord content from these 2 groups. Although it is true that other chords are also used, they are all embellishments (7th chords, 9th chords etc), slight alterations (suspended chords) or chord inversions. These can be thought of as extensions of these same chords. Having working knowledge of this information is invaluable, especially in conjunction with training the ear.

©2012 Jim Greenfield