Dorian mode

Dorian is the second of the seven modes: on a piano it is the white keys from D to D, D E F G A B C D. Moved to start on A, it becomes A B C D E F# G A, which is easiest to see next to A natural minor:

The F# changes the chords that contain it. The iv chord of A minor, Dm (D F A), becomes a major IV, D (D F# A), and Bdim (B D F) becomes Bm (B D F#). Rocking between Am and D, or Am7 and D7, is the classic Dorian vamp: the home chord stays minor while the major IV lifts it, so it sounds cool and a little hopeful where natural minor sounds sad.

The full set of chords in A Dorian is Am, Bm, C, D, Em, F#dim and G (i ii III IV v vi° VII). Those are the chords of G major, because A Dorian uses G major’s notes with A as home. In the same way, D Dorian uses the same notes as C major and its relative minor, A minor, with D as home.

Miles Davis’s “So What”, the opening track of Kind of Blue (1959), is the textbook example: 16 bars of D Dorian, 8 bars of Eb Dorian, then 8 more of D Dorian.

To hear it, loop Am and D and play over them on the white keys, with F# in place of F. Then change the D chord to Dm, go back to F, and listen to the mood drop.

Gelato Synth and Gelato Chord both include Dorian as a scale. The 7 music modes by mood compares Dorian with its neighbors, and the A minor page lists the natural minor chords to hold it up against.