Non Diatonic Chords

What about songs that are not in the same key?


View the full lesson at Non Diatonic Chords | JustinGuitar

When maj7 chords appear in a chord progression, are there any clues to guessing what key the progression is in? Like do maj7 chords commonly replace certain scale degrees? For example, they only can be in I, IV, V? Or can they appear anywhere?

Are Maj7 chords simply the addition of the VII degree note into the regular Maj chord?

I was playing Rocksmith, practicing rhythm arrangements and on the song Hey Ya! by Outkast, the chord progression is G, C, D, E. If you were trying to figure out the key of a progression like that for a solo or something, what would you do with that?

It fits closest to the Key of G, but has an E maj instead of a E min. We would just call this a non diatonic chord progression and work with the key it fits closest into?

I suggest running through Richard’s wonderful thread on the old forum about borrowed chords. This one seems like a clear example where you borrow E maj from G minor scale long story short. How to improvise is itself a big topic as you are entering muddy waters of Modes :slight_smile:

https://justinguitarcommunity.com/index.php?topic=50073.0

1 Like

In any set of seven diatonic chords there are three major and three minor plus a diminished.
Of the three majors (I, IV and V respectively), when extended from a triad formula to a four-note form (JUstin calls these quadads) one and one only becomes a 7, the other two become major 7.
The I (root) and the IV both become major 7.
Only the V, the dominant, becomes a 7 and is, naturally called a dominant 7.

This is all due to the immutable and inevitable consequence of constructing such chords by stacking in thirds.
Take the key of E major.
I chord = E major
IV chord = A major
V chord = B major

E major scale (multiples of):
image

The I chord
1, 3, 5 = E, G#, B = E major
When extended
1, 3, 5, 7 = E, G#, B, D# = E major 7
The interval from E to D# is a major 7th (11 semitones - check the Note Circle).

The IV chord
4, 6, 8 = A, C#, E = A major
When extended
4, 6, 8, 10 = A, C#, E, G# = A major 7
The interval from A to G# is a major 7th (11 semitones - check the Note Circle).
When written as a chord formula in relation to its own root, it takes the form 1, 3, 5, 7 - just as the I chord does.

The V chord
5, 7, 9 = B. D#, F# = B major
When extended
5, 7, 9, 11 = B. D#, F#, A = B major 7
The interval from B to A is a minor 7th (10 semitones - check the Note Circle).
When written as a chord formula in relation to its own root, it takes the form 1, 3, 5, b7 - different from the I and IV chords.

Both the I and IV extend to become major 7.
Only the V chord becomes a dominant 7.

Hope that helps.

Cheers :smiley:
| Richard_close2u | JustinGuitar Official Guide & Moderator

1 Like

That does help, thanks! :+1: :+1: