semicord

Ab13 Ab dominant thirteenth chord

Notes
Ab C Eb Gb Bb Db F
Formula
1 3 5 b7 9 11 13
Semitones
0 4 7 10 14 17 21 above the root
Also written
G#13 (G# B# D# F# A# C# E#)
Other symbols
Abdom13

Ab to C is a major third (4 semitones), C to Eb is a minor third (3 semitones), Eb to Gb is a minor third (3 semitones), Gb to Bb is a major third (4 semitones), Bb to Db is a minor third (3 semitones), Db to F is a major third (4 semitones). A dominant seventh with the thirteenth, F, on top. The full chord has seven notes and a guitar has six strings, so players keep the root, the third C, the seventh Gb and the thirteenth F, and leave out the fifth, the ninth and above all the eleventh Db, which clashes with the third. The thirteenth is the sixth an octave up; it is a 13 and not a 6 chord because the seventh is there.

Ab13 on the piano

C4D4E4F4G4A4B4C5D5E5F5G5A5B5C6D6E6F6G6A6B6C#4Eb4F#4Ab4Bb4C#5Eb5Gb5Ab5Bb5Db6Eb6F#6Ab6Bb6C4AbCC5EbGbBbC6DbF

Root position from Ab4: Ab4, C5, Eb5, Gb5, Bb5, Db6, F6. Middle C is C4.

Ab13 on the guitar

Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has Ab as its lowest note.

4frAbAb×GbGbCCFF×
E-shape, root on the E string at fret 4
4 x 4 5 6 x (low E to high e)
Sounds Ab2 Gb3 C4 F4, fifth, ninth and eleventh left out
11fr×AbAb×GbGbCCFF
A-shape, root on the A string at fret 11
x 11 x 11 13 13 (low E to high e)
Sounds Ab3 Gb4 C5 F5, fifth, ninth and eleventh left out

The E-shape and A-shape grips are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play dominant thirteenth chords on other roots.

Inversions of Ab13

An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.

PositionNotes, bass firstNamedListen
Root positionAb C Eb Gb Bb Db FAb13
1st inversionC Eb Gb Bb Db F AbAb13/C
2nd inversionEb Gb Bb Db F Ab CEbm13 (also read as Ab13/Eb)
3rd inversionGb Bb Db F Ab C EbAb13/Gb
4th inversionBb Db F Ab C Eb GbAb13/Bb
5th inversionDb F Ab C Eb Gb BbAb13/Db
6th inversionF Ab C Eb Gb Bb DbAb13/F

Where Ab13 fits

Ab13 is V13 in Db major. Played with its third, seventh and thirteenth (C, Gb, F) over the root, it is the standard dominant chord of jazz and soul, resolving to Db.