Dorian Mode

Dorian is a minor mode — it has a minor third — but the raised sixth degree (compared to natural minor) gives it a lift that pure minor doesn't have. It's the most commonly used mode after Ionian and Aeolian, and it's the modal sound most associated with jazz, funk, and 60s rock. "So What" by Miles Davis is the canonical example.

Construction

Parent major scale shifted to start on the 2nd degree.
D Dorian = C major scale starting on D:
D E F G A B C D

Formula (compared to major scale):
1  2  ♭3  4  5  6  ♭7

Step pattern: W - H - W - W - W - H - W

Compared to D natural minor (D E F G A B♭ C D), Dorian has a natural 6th (B natural instead of B♭). That one note makes the difference.

Sound and Character

The raised 6th against the minor 3rd is what defines Dorian's sound. It's simultaneously melancholy and warm — darker than major but warmer than natural minor. The major IV chord (built on the 4th degree) is uniquely Dorian: in D Dorian that's G major, which shares no note with D minor but fits perfectly because the B natural is in the scale. Playing D minor over Dm but emphasising the B natural and building a G major chord from the bass is instantly recognisable as Dorian.

Key Scales for Reference

D Dorian:  D  E  F  G  A  B  C  D
A Dorian:  A  B  C  D  E  F#  G  A
E Dorian:  E  F# G  A  B  C#  D  E
G Dorian:  G  A  B♭ C  D  E  F  G

Characteristic Chords

In D Dorian:
Im7:  Dm7  (tonic, home)
IV:   G    (the Dorian IV — major, uniquely Dorian vs. natural minor)
♭VII: C    (borrowed from natural minor territory, common)
ii°:  Em7♭5 (half-diminished, less common)

The Im7 → IV move is the sound of Dorian. Play Dm7 to G major and you've got it. That exact move appears in "So What," "Oye Como Va," "Scarborough Fair," and countless other Dorian tunes.

Where to Use It

Dorian works over minor seventh chords (m7) in a jazz or modal context where you want minor colour without the darkness of natural minor. In a ii-V-I progression, the ii chord (Dm7 in C major) is technically Dorian — the notes of the C major scale starting on D. Over sustained minor chords (modal jazz, vamps) Dorian is often preferable to Aeolian because the raised 6th gives more melodic options and a less gloomy sound.