Chords belonging to the key of A flat major
The chart below lists the common chords in the key of 
A flat major. The first row are triads and four note 
voicings in the second row. Roman numerals indicate 
each chords position relative to the scale.

A flat major scale notes: Ab Bb C Db Eb F G
Major key chord sequence: Maj min min Maj Maj min dim
Note: The same chords and scale notes are used for the 
key of G sharp major but this key isn't used often 
because of notation difficulties caused by the need 
for a double sharp.

I	ii	iii	IV	V	vi	vii
Abmaj	Bbmin	Cmin	Dbmaj	Ebmaj	Fmin	Gdim
Abmaj7	Bbmin7	Cmin7	Dbmaj7	Eb7	Fmin7	Gm7b5
Common chord progressions in A flat major
I - IV - V	Ab - Dbmaj - Ebmaj
I - vi - IV - V	Ab - Fmin - Dbmaj - Ebmaj
ii - V - I	Bbmin7 - Eb7 - AbM7