A13 A dominant thirteenth chord
- Notes
- A C# E G B D F#
- Formula
- 1 3 5 b7 9 11 13
- Semitones
- 0 4 7 10 14 17 21 above the root
- Other symbols
- Adom13
A to C# is a major third (4 semitones), C# to E is a minor third (3 semitones), E to G is a minor third (3 semitones), G to B is a major third (4 semitones), B to D is a minor third (3 semitones), D 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 G and the thirteenth F#, and leave out the fifth, the ninth and above all the eleventh D, 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.
A13 on the piano
Root position from A4: A4, C#5, E5, G5, B5, D6, F#6. Middle C is C4.
A13 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 A as its lowest note.
x 0 x 0 2 2 (low E to high e)
Sounds A2 G3 C#4 F#4, fifth, ninth and eleventh left out
5 x 5 6 7 x (low E to high e)
Sounds A2 G3 C#4 F#4, 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 A13
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.
| Position | Notes, bass first | Named | Listen |
|---|---|---|---|
| Root position | A C# E G B D F# | A13 | |
| 1st inversion | C# E G B D F# A | A13/C# | |
| 2nd inversion | E G B D F# A C# | Em13 (also read as A13/E) | |
| 3rd inversion | G B D F# A C# E | A13/G | |
| 4th inversion | B D F# A C# E G | A13/B | |
| 5th inversion | D F# A C# E G B | A13/D | |
| 6th inversion | F# A C# E G B D | A13/F# |
Where A13 fits
A13 is V13 in D major. Played with its third, seventh and thirteenth (C#, G, F#) over the root, it is the standard dominant chord of jazz and soul, resolving to D.