How to form diatonic chords of A flat major scale?

A Flat Major Scale

A♭ – B♭ – C – D♭ – E♭ – F – G – A♭ are the notes of the A flat major scale.

Diatonic chords are formed by stacking two generic third notes above each scale note.

A Flat Major Diatonic Chords

These are the seven major scale diatonic chords that come from the A Flat major scale.

Each major scale diatonic chord is labelled with a roman numeral number, and follows the same pattern:

I,  ii,  iii,  IV,  V,  vi, viiº

We use uppercase roman numeral numbers to represent major chords, lowercase to represent minor chords, uppercase with a small plus sign to represent augmented chords, and lowercase with a small circle to represent diminished chords.

First, fourth and fifth chords of a major scale will always be major chords. Second, third and sixth chords of a major scale will always be minor chords. Seventh chord of a major scale will always be diminished chords.

The seven diatonic chords formed from the key of A flat major are:

I.   A♭ – C – E♭ (A Flat major chord)

ii.   B♭ – D♭ – F (B Flat minor chord)

iii.   C – E♭ – G (C minor chord)

IV.   D♭ – F – A♭ (D Flat major chord)

V.  E♭ – G – B♭ (E Flat major chord)

vi.  F – A♭ – C (F minor chord)

viiº.  G – B♭ – D♭ (G diminished chord)

These are the chords that are diatonic to the A flat major scale. They are directly related to the A flat major key and make a harmonic sound for music in the same key.