Dorian

The note that defines it

C D E♭ F G A B♭, then C. Compare with C natural minor, which has A♭ where this has A natural. The raised sixth is the whole difference, and it is what makes a Cm7 chord sound open rather than heavy.

The scale is the second mode of B♭ major, so its notes are identical to that key. Playing B♭ major starting from C is a way to find it without memorising a new pattern.

On the fretboard

From the eighth fret with the root on the low E string, the movable dorian shape covers two octaves. Guitarists usually learn it as the minor pentatonic with two added notes, which is how it appears in solos.

The A natural is the note to lean on: it is what tells the listener this is dorian and not natural minor, and a solo that avoids it loses the character entirely.

Where it is used

Modal jazz above all — a single Cm7 chord held while the melody draws on the raised sixth. Funk uses the same device with a static bass line.

It also appears in rock whenever a minor riff includes the major sixth: the sound is neither blues nor classical minor, and dorian is the name for it.

The clearest way to hear the difference is to play the same riff twice, once with A♭ and once with A natural. Nothing else changes, and the second version stops sounding like a lament.