A13 — A dominant thirteenth chord
A dominant seventh chord with the ninth and the thirteenth added. The eleventh is left out because it clashes with the third; with the eleventh included the chord has seven distinct notes.
- 1 = A
- 9 = B
- 3 = C#
- 5 = E
- 13 = F#
- b7 = G
- Symbol
- A13
- Root
- A
- Quality
- Dominant thirteenth
- Family
- extended
- Notes
- A B C# E F# G
- Degree formula
1 9 3 5 13 b7- Semitones from the root
0 2 4 7 9 10- Distinct pitch classes
- 6
- Interval structure
- Stacked from the root: 2 semitones, 2 semitones, 3 semitones, 2 semitones, 1 semitones
- Notation
- Written 13. Common as a final chord in blues, and as a dominant with colour in jazz.
- Key
- A · A major / F# minor key signature
Formula
The chord tones in order from the root, with the interval each one forms above it.
| Degree | Note | Semitones | Interval from the root |
|---|---|---|---|
| 1 | A | 0 | Perfect unison |
| 9 | B | 2 | Major second |
| 3 | C# | 4 | Major third |
| 5 | E | 7 | Perfect fifth |
| 13 | F# | 9 | Major sixth |
| b7 | G | 10 | Minor seventh |
Inversions
An inversion is the same set of notes with a different one in the bass. The last column gives the distance of each note above the bass note, in semitones.
| Inversion | Bass note | Degree in the bass | Notes above the bass | Semitones above the bass |
|---|---|---|---|---|
| root position | A | 1 | A – B – C# – E – F# – G | 0 2 4 7 9 10 |
| first inversion | B | 9 | B – C# – E – F# – G – A | 0 2 5 7 8 10 |
| second inversion | C# | 3 | C# – E – F# – G – A – B | 0 3 5 6 8 10 |
| third inversion | E | 5 | E – F# – G – A – B – C# | 0 2 3 5 7 9 |
| fourth inversion | F# | 13 | F# – G – A – B – C# – E | 0 1 3 5 7 10 |
| fifth inversion | G | b7 | G – A – B – C# – E – F# | 0 2 4 6 9 11 |
Playable voicings
These shapes were found by searching the fretboard of a standard-tuned guitar (E A D G B E) rather than copied from a chord book. The search allows every string to sound or to be muted, rejects any shape with a muted string between two sounding strings, rejects any shape whose fretted notes span more than four frets (a five-fret window), requires every chord tone to be present, and then sorts what remains with root-position shapes first and the most compact, lowest shapes next. The shapes shown are the first six of that ordering; other orderings are possible at the same frets.
| # | Shape (low string first) | Notes | Degrees | Bass | Span (frets) | Sounding strings |
|---|---|---|---|---|---|---|
| 1 | 5-4-4-4-5-3 | A C# F# B E G | 1 3 13 9 5 b7 | A | 2 | 6 |
| 2 | 5-7-5-6-7-7 | A E G C# F# B | 1 5 b7 3 13 9 | A | 2 | 6 |
| 3 | 5-4-5-4-5-2 | A C# G B E F# | 1 3 b7 9 5 13 | A | 3 | 6 |
| 4 | 5-2-4-6-5-3 | A B F# C# E G | 1 9 13 3 5 b7 | A | 4 | 6 |
| 5 | 5-2-5-6-5-2 | A B G C# E F# | 1 9 b7 3 5 13 | A | 4 | 6 |
| 6 | 5-7-4-6-8-7 | A E F# C# G B | 1 5 13 3 b7 9 | A | 4 | 6 |
Shape numbers run from the lowest string to the highest, so the left-hand number is the sixth string (low E) in standard tuning. Multiple shapes are listed because a chord can be voiced several ways, and because a lower position is not always the better sounding one.
Related chords and scales
- KeyEverything in A
- ScaleA mixolydian
- ChordA9
- ChordA7
Related
- KeyKey of A
- ScaleA mixolydian
- ChordA9 — Dominant ninth
- ChordA7 — Dominant seventh
- ChordA11 — Dominant eleventh
- ChordAm11 — Minor eleventh
- ChordAm9 — Minor ninth
- DegreesA — degree map