Cm13

Cm13 is a seventh-chord extension built on C minor. It combines the basic C minor triad with a minor seventh and added extensions: the ninth, eleventh, and thirteenth. In its full form, the chord comprises the notes C, Eb, G, Bb, D, F, and A. Because some extensions can clash with other tones in a given arrangement, many voicings omit the fifth (G) or the eleventh (F) or rearrange the notes across voices.

Structure and notes

- Root: C

- Minor third: Eb

- Fifth: G (often omitted in compact voicings)

- Minor seventh: Bb

- Ninth: D

- Eleventh: F

- Thirteenth: A

A Cm13 chord can be heard as Cm7 with added 9, 11, and 13 tensions. Because the 11th can create dissonance with the minor third, practitioners frequently use versions that omit the 11th or place it in a different octave.

Voicings and usage

Common voicings place the root or the root with the seventh in the bass and distribute the upper tensions across the right hand or higher strings. On guitar, a typical approach is to include C, Eb, Bb, D, and A, leaving out F or G as needed. On keyboards, a pianist might play C in the left hand with Eb, Bb, D, F, and A in the right hand, or omit some notes for a smoother texture. Cm13 is widely used in jazz, fusion, and pop to color a minor ii-V-I progression, function as a tonic minor color, or as a passing extension between chords.

Notation and related chords

Cm13 can be written as Cm13 or Cm7(9,11,13). It is related to Cm7, Cm9, and Cm11 by common extensions, with the 13th providing a distinctive final color.