Ab is Ab, C and Eb.
It sounds plain and completely at rest. The reference every other chord on this page is a modification of.
Tonic — the chord a progression stops on.
Also written Abmaj, AbM or Ab major.
The chord a minor scale builds on its fifth degree is minor, but Ab is what gets played there. Its major third is the leading tone, a half step below the root of C#m; without it the chord doesn’t sound like a dominant.
Listen for: The leading tone rises a half step to the root of the i. On the minor v the same string is a whole step below it, and the pull is gone.
Ab is the IV of Eb, which is the IV of Bb: two plagal steps in a row, each a fourth up. The same pair of neighbour notes falls in each step, a rock staple since the mid-sixties.
Listen for: One voice steps down twice, a half step and then a whole step, from the flat seventh of the key to its fifth.
Heard in“Gloria”“I Can’t Explain”“Hey Jude” (coda)
In which keys. Every note of Ab belongs to C minor, C# major, Eb major, F minor, Ab major and Bb minor.
Every note of Ab is in Ab major pentatonic, 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 Ab sits in it. Every scale.
Change one note of Ab and you have (the major third becomes the minor third), (the major third becomes the second), (the major third becomes the fourth), (add the major seventh), (add the ninth) or (drop the major third).
Ab 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.