Ab13

Ab13 is Ab, C, Eb, Gb, Bb and F, a dominant thirteenth. The shape this page opens on is written 413112, lowest string first.

Also written Abdom13 or Ab dominant 13. The same chord either way; which spelling you meet depends on who wrote the chart.

There are 7 common shapes for Ab13 on the guitar, and 47 derived voicings in 4 families.

In which keys. Every note of Ab13 belongs to C# major (the V) and Bb minor (the ♭VII).

The common shapes, written lowest string first: 413112, 433342, 444566, 464564, x-11-10-11-13-13, x-11-10-11-11-13, 11-11-11-11-13-13.

Shell. 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. Ab13 has 4x456x, x-11-x-11-13-13.

Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. Ab13 has xx3112, 2331xx, xx4564, x-9-10-10-9-x, x-x-15-13-13-14, 14-15-15-13-x-x, 4845xx, x8657x.

Drop 3. The third voice from the top lowered an octave. The dropped voice becomes the bass, which is why a string is skipped. Ab13 has 2x311x, x8x574, 4x456x, 8-x-6-10-7-x, x-9-x-10-9-8, 13-x-10-11-9-x, x-11-x-11-13-13, 14-x-15-13-13-x.

Rootless. The root left to the bass player. Frees a finger for a tension. Ab13 has xx3312, xx4566, x6456x, x-9-10-10-11-x, x-x-13-11-13-13, x-x-15-15-13-14, x3x362, x6x562.

Tensions. A shell of Ab13, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (D).

The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.