Minor 13th
m13
0 - 3 - 7 - 10 - 14 - 21Minor11 + major 13th
About Minor 13th
A minor thirteenth chord is a minor eleventh with a thirteenth on top, or a minor ninth with a major sixth added — in C that is C, E♭, G, B♭, D and A, written Cm13. The A is a major sixth above the root even though the chord is minor, and that raised note is what makes it a Dorian chord rather than a mournful one.
Notes and formula
The formula is 1 – ♭3 – 5 – ♭7 – 9 – 13, or 0 – 3 – 7 – 10 – 14 – 21 in semitones. The eleventh is usually present too in a full voicing, since nothing in a minor chord objects to it.
The thirteenth is major. A minor thirteenth chord with a lowered sixth is not this chord and is not normally written — the raised sixth is the whole reason the symbol exists.
How to play it
On guitar the practical form is x31335, sounding C–E♭–B♭–D–A. The fifth goes, as always, and the shape is a minor ninth with one more finger.
On piano the reliable voicing is C in the left hand and E♭–B♭–D–A above it. Keep the A clearly at the top: buried in the middle it starts to sound like a passing note rather than part of the chord.
Why it sounds bright for a minor chord
The raised sixth is the note that separates Dorian from the natural minor scale, and hearing it inside the tonic chord makes the mode explicit. A listener does not need the melody to establish it.
That is why the chord reads as cool rather than sad. Minor harmony with a raised sixth has been the sound of modal jazz, funk and neo-soul for sixty years, and this chord states it in a single stack.
Where you hear it
On the ii chord of a jazz progression when the arranger wants more than a minor ninth, and as a standing tonic in modal and groove-based writing.
It is also the chord that turns a static minor vamp interesting: hold Cm7 for eight bars and it flattens out, hold Cm13 and it does not, because the sixth keeps suggesting a scale rather than a chord.
Minor thirteenth or minor sixth-ninth
Cm6/9 is C–E♭–G–A–D: the same raised sixth, the same ninth, and no seventh. Cm13 adds B♭ underneath.
The seventh decides whether the chord loops or closes. Without it the chord sounds final, which is why arrangers end minor pieces on a sixth-ninth; with it the chord stays open, which is why they vamp on a thirteenth.
Scales that contain it
Dorian, and essentially only Dorian. Aeolian lowers the sixth degree, which contradicts the chord's defining note, and Phrygian lowers the second, which contradicts its ninth.
This is unusual and worth remembering: most chords tolerate several modes, and this one names its scale outright.
Frequently asked questions
What notes are in a Cm13 chord?
C, E♭, G, B♭, D and A, with the eleventh often added as well. On guitar the working shape is x31335.
Why is the thirteenth major in a minor chord?
Because the chord comes from Dorian, where the sixth degree is raised. A minor chord with a lowered sixth is a different sonority and is written differently.
What is the difference between Cm13 and Cm6/9?
The seventh. Cm6/9 has none and sounds closed, which suits a final chord; Cm13 includes B♭ and stays open, which suits a vamp.