Cm7 is C, Eb, G and Bb — with the flat seventh added.
It sounds smooth and unhurried. The workhorse of the family, and the chord soul, funk and jazz comp on more than any other.
Pre-dominant — the ii of a major key, and a tonic in its own right.
Also written Cmin7, C-7 or C minor 7.
Cm7 is the ii of B♭ major: it leads to the dominant a fourth higher. ii–Vs can be chained so each dominant leads to the next ii, and each minor chord’s seventh falls a half step to the next dominant’s third.
Listen for: One line walks down a half step per chord through the whole chain, and holds on the last as the major seventh.
Cm7 has exactly the notes of Eb6. Hold the shape and put the key’s root under it, and the vi chord becomes the I. That is why the vi can stand in for the home chord.
Listen for: Only the bass moves, up a minor third. The four notes above it never change.
Cm7 is the vi of the basic turnaround in E♭ major. In jazz it is usually replaced by an altered dominant on the same root.
When a minor ii–V lands on Cm7 and the chord lasts two bars, the second bar can turn it into Cm6 or a minor-major seventh, melody permitting.
In which keys. Every note of Cm7 belongs to C minor, Eb major, F minor, G minor, Ab major and Bb major.
Every note of Cm7 is in C minor pentatonic, C blues, C natural minor, C dorian and C phrygian.
Each of those is a page: the scale across the neck, and the chords it harmonises into — which is where Cm7 sits in it. Every scale.
Change one note of Cm7 and you have (drop the flat seventh), (the flat seventh becomes the sixth), (the fifth becomes the flat fifth), (add the ninth), (the flat seventh becomes the major seventh) or (the flat seventh becomes the ninth).
Cm7 is a minor chord — root, minor third, fifth. Minor chords on every root.
The common shapes and the derived voicings come from different places, and both are explained in how this site is built.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.