Non Diatonic Chords

Music Theory Chords In Keys & Common Progressions
42

@roby2

My preference and habit is to always use upper case for major chords and lower case for minor / diminished chords.

Justin does not use this method however. You will notice that in all his theory lessons he uses upper case Roman numerals.

When the chords are diatonic, he simply lists them as I, II, III, IV, V, VI, VII and such a method implies a tacit knowledge and understanding of the fact that:
I = major
II = minor
III = minor
IV = major
V = major
VI = minor
VII = diminished

Such is the sequence of chords in every major key.

It does mean that any time a non-diatonic chord is part of a chord progression, the Roman numeral plus a suffix (identifying the chord type) is needed. As in the lesson, there is a need to write IV minor for example. If using upper and lower case these suffixes are not needed.

Here is one set of entirely diatonic chords written in two ways

1]
All upper case

| C  | Dm | C  | Am | C  | F  | G7 | C  |

| I  | II | I  | VI | I  | IV | V7 | I  |

2]
Upper and lower case

| C  | Dm | C  | Am | C  | F  | G7 | C  |

| I  | ii | I  | vi | I  | IV | V7 | I  |

Here is a set of chords with a mix of diatonic and non-diatonic written in two ways

1]
All upper case

| C  | Dm | Bb      | Am | C  | D     | G7 | C  |

| I  | II |bVII Maj | VI | I  |II Maj | V7 | I  |

2]
Upper and lower case

| C  | Dm | Bb   | Am | C  | D  | G7 | C  |

| I  | ii | bVII | vi | I  | II | V7 | I  |

Both options are ‘correct’. Whether one is better or worse, or a preference, is down to personal choice. Justin uses his method so you do need to know it and learn according to it for the purposes of PMT.

I hope that helps.
:slight_smile:

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43

I got close on the quiz. For Eb in the key of A, I called it bV while the answer key has bVMaj. I figured since the V is usually major, I didn’t need to add that to the chord name. Is that wrong?

Full disclosure, I also missed F in the key of A. I called it VIMaj when it’s actually bVIMaj. I understand my mistake: A major scale has F#, so F is the bVI.

Added later: Nevermind on my question. I read through the comments in this section and see that you answered it to Bane in Jan 2024.

Cheers!

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