Ab69 is Ab, C, Eb, F and Bb — with the ninth added as well.
It sounds wide and entirely at rest. The modern way to voice a tonic when a triad is too bare and a maj7 too pointed.
Tonic — it commits to nothing.
Also written Ab6/9, Ab6add9 or Ab six nine.
Where a tune’s home chord is written as a major seventh or sixth, Ab69 is often played instead. It is A♭ major’s sixth chord with one note raised a whole step, root to ninth.
Listen for: The ii’s root holds through the V as its fifth and stays on as the ninth of the I. On the sixth chord it falls a whole step to the root.
In which keys. Every note of Ab69 belongs to C minor, C# major, Eb major, F minor, Ab major and Bb minor.
Ab69 is every note of the Ab major pentatonic, and nothing else. It also sits inside Ab major, Ab mixolydian, Ab lydian and Ab lydian dominant.
Each of those is a page: the scale across the neck, and the chords it harmonises into — which is where Ab69 sits in it. Every scale.
Change one note of Ab69 and you have (the sixth becomes the major seventh), (add the major seventh), (the major third becomes the minor third), (drop the sixth), (drop the ninth) or (the sixth becomes the flat seventh).
Ab69 is a major chord — root, major third, fifth. Major chords on every root.
The common shapes and the derived voicings come from different places, and both are explained in how this site is built.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.