Root, third and seventh: the guide tones fix the quality, so the fifth is dropped. That is what leaves a string free, so pick a tension to put on top.
Ab6 is Ab, C, Eb and F — Ab with a major sixth added on top.
It sounds warm, and finished without being sweet. It closes a tune as firmly as the triad does but without the maj7’s shine, which is why so many standards end on one.

| Ab | C | Eb | F |
|---|---|---|---|
| 1 | 3 | 5 | 6 |
Tonic — an ending chord.
Also written Abmaj6, AbM6 or Ab major 6. The same chord either way; which spelling you meet depends on who wrote the chart.
Root, third and seventh. The third and seventh, the guide tones, are what make the chord major, minor or dominant, so the fifth can go: it says nothing the symbol needs.
Three notes means a spare string, which is the real point. Put a tension on it.
Ab6 has 4 of them, on the bottom three strings, the low-middle three, strings 6-4-3 and strings 5-3-2, from the 3rd fret up to the 10th — all in one inversion, so the bass note never moves. The one to learn first is the Ab shape at the 3rd fret, which is the easiest grip here.
Start with 4x354x — no barre and low, at the 3rd fret. None of the shapes for Ab6 uses an open string, so every one of them is movable; the lowest sits at the 1st fret. 4 of the 9 need a barre. Together they cover the neck from the 1st fret to the 13th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x31111 | 1st fret | C, 1st inversion | F | barred |
| 433111 | 1st fret | Ab, root position | F | barred |
| 131141 | 1st fret | F, 6th in the bass | F | barred |
| 4x354x | 3rd fret | Ab, root position | Eb | all fretted |
| 4x6564 | 4th fret | Ab, root position | Ab | all fretted |
| 46x564 | 4th fret | Ab, root position | Ab | all fretted |
| xx6868 | 6th fret | Ab, root position | C | all fretted |
| x-11-10-10-9-x | 9th fret | Ab, root position | Ab | all fretted |
| x-11-13-13-13-13 | 11th fret | Ab, root position | F | barred |
The same notes rebuilt from scratch give 14 drop 2 and 9 drop 3 voicings, each on its own page.
Tensions. A shell of Ab6, root, third and seventh, leaves a string free, and the tones that belong over it are the 9 (Bb) and the #11 (D).
How you get to it. The turn that lands on Ab6 is Bbm7 to Eb7 — the ii and the V of Ab — and Eb7 shares its third and seventh with Bbm7, so the hand barely moves between them.
In which keys. Every note of Ab6 belongs to C minor (the ♭VI), C# major (the V), Eb major (the IV), F minor (the ♭III), Ab major (the I) and Bb minor (the ♭VII).
Every note of Ab6 is in Ab major pentatonic, Ab major, Ab lydian, Ab mixolydian and Ab lydian dominant.
Change one note of Ab6 and you have Ab (drop the sixth), Abmaj7 (the sixth becomes a major seventh), Abm6 (the major third becomes a minor third), Abadd9 (the sixth becomes a ninth), Ab69 (add the ninth) or Ab7 (the sixth becomes a flat seventh).
Ab6 is a major chord — root, major third, fifth. Major chords on every root.
On Ab6’s sound and use this page follows Mark Levine, The Jazz Piano Book (Sher Music, 1989). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.