My Guitar Notes

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.

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.

DegreeNoteSemitonesInterval from the root
1A0Perfect unison
9B2Major second
3C#4Major third
5E7Perfect fifth
13F#9Major sixth
b7G10Minor 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.

InversionBass noteDegree in the bassNotes above the bassSemitones above the bass
root positionA1A – B – C# – E – F# – G0 2 4 7 9 10
first inversionB9B – C# – E – F# – G – A0 2 5 7 8 10
second inversionC#3C# – E – F# – G – A – B0 3 5 6 8 10
third inversionE5E – F# – G – A – B – C#0 2 3 5 7 9
fourth inversionF#13F# – G – A – B – C# – E0 1 3 5 7 10
fifth inversionGb7G – 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)NotesDegreesBassSpan (frets)Sounding strings
15-4-4-4-5-3A C# F# B E G1 3 13 9 5 b7A26
25-7-5-6-7-7A E G C# F# B1 5 b7 3 13 9A26
35-4-5-4-5-2A C# G B E F#1 3 b7 9 5 13A36
45-2-4-6-5-3A B F# C# E G1 9 13 3 5 b7A46
55-2-5-6-5-2A B G C# E F#1 9 b7 3 5 13A46
65-7-4-6-8-7A E F# C# G B1 5 13 3 b7 9A46

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

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