Minor Seventh Chord
A minor seventh chord combines a minor triad with a minor seventh. Cm7 contains C, E flat, G and B flat. It can function as a modal tonic, as ii in B-flat major or as vi in E-flat major, so context matters as much as the chord type.
- 1-flat 3-5-flat 7
- minor triad
- minor seventh
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Which notes are in Cm7?
Use the formula 1-flat 3-5-flat 7:
- C: root
- E flat: minor third
- G: perfect fifth
- B flat: minor seventh
The symbol is Cm7, Cmin7 or sometimes C-7.
How do you build it?
Start with the minor triad C-E flat-G and add B flat, ten semitones above C.
The chord stacks a minor third, major third and minor third from bottom to top in close root position.
Transpose the scale-degree formula. Fm7 is F-A flat-C-E flat; Am7 is A-C-E-G.
Where does it occur in a major key?
Minor-seventh chords occur on degrees ii, iii and vi.
In B-flat major, Cm7 is ii and commonly moves to F7, then B-flatmaj7.
In E-flat major, Cm7 is vi. The same notes receive a different function because the tonic and surrounding chords change.
Can m7 be a tonic chord?
Yes. Cm7 can act as tonic in C Dorian, C Aeolian-influenced harmony, blues-related music and modal vamps.
C Dorian contains A natural; C Aeolian contains A flat. Both contain the four Cm7 chord tones.
The extensions and other chords reveal the broader modal collection.
Does Cm7 contain a tritone?
No. E flat to B flat is a perfect fifth, and C to G is another.
C7 changes E flat to E, producing the tritone E-B flat. That guide-tone pair gives C7 its common dominant pull.
Cm7 can still move strongly in a progression; the motion comes from context and voice leading instead of an internal dominant tritone.
What is the difference between Cm7 and Cm?
Cm is C-E flat-G. Cm7 adds B flat.
The extra note can connect smoothly to surrounding chords and provides flat 7 as a melodic or harmonic color.
Remove B flat and the underlying minor triad remains complete.
How does it compare with Cm6 and CmMaj7?
Cm6 is C-E flat-G-A. CmMaj7 is C-E flat-G-B.
Cm7 uses B flat. The three chords keep C, E flat and G while changing the fourth tone by semitone or whole step.
Their scale contexts differ: Cm6 often fits C Dorian, CmMaj7 fits harmonic or melodic minor, and Cm7 fits several natural-minor or modal settings.
How do inversions work?
Cm7 has four bass positions:
- Root position: C-E flat-G-B flat
- First inversion: E flat-G-B flat-C
- Second inversion: G-B flat-C-E flat
- Third inversion: B flat-C-E flat-G
Slash symbols such as Cm7/E flat specify an inversion when the bass is a chord tone.
Which notes can you omit?
Keep E flat for minor quality and B flat for the seventh.
The unaltered fifth G can often be omitted. The root C may be left to the bass player.
A shell voicing E-flat-B-flat supplies the guide tones, although the bass is needed to make the root unambiguous.
How should you practice it?
Build Cm, Cm7, Cm6 and CmMaj7 while holding C, E flat and G.
Play Cm7-F7-B-flatmaj7 and identify Cm7 as ii. Then loop Cm7-F7 with C in the bass and hear how function changes when C remains central.
Transpose Cm7 to Fm7 and B-flatm7 from the formula.