Dorian Mode

Dorian is a minor mode with a raised sixth degree. That one note — compared to natural minor — gives it a lift and warmth that pure minor doesn't have. It's the most widely used minor mode in jazz, funk, and 60s rock. "So What" by Miles Davis is the canonical example; one chord, two modes (D Dorian and E♭ Dorian), sixteen bars each, and a generation of musicians found a new way to hear minor harmony.

Construction

The second mode of the major scale — starts on the 2nd degree.
D Dorian = C major scale starting on D:
D E F G A B C D

Formula:      1  2  ♭3  4  5  6  ♭7
Step pattern: W  H  W   W  W  H  W

Compare to D natural minor (Aeolian): D E F G A B♭ C D
The B is natural in Dorian (B♭ in Aeolian) — that one note is the difference.

Dorian in Common Keys

Dorian root	Notes	Parent major key
D Dorian	D E F G A B C	C major
E Dorian	E F# G A B C# D	D major
A Dorian	A B C D E F# G	G major
G Dorian	G A B♭ C D E F	F major
B Dorian	B C# D E F# G# A	A major
F# Dorian	F# G# A B C# D# E	E major

Sound and Character

Simultaneously melancholy and warm — darker than major but brighter than natural minor. The major 6th sitting against the minor 3rd is the defining colour: it's an optimistic note inside a minor scale. The major IV chord (built on the 4th degree) is uniquely Dorian — in D Dorian that's G major. In natural minor the iv chord is minor (Dm in A Aeolian). The G major chord in D Dorian gives a lift that Aeolian iv doesn't have.

Characteristic Chords

Chord	In D Dorian	Character	Uniquely Dorian?
Im7	Dm7	Tonic — minor, settled	Same as Aeolian
IV (major)	G major	The Dorian IV — major, lifted	Yes — Aeolian has minor iv (Dm)
♭VII	C major	Subtonic — common in rock and jazz	Same as Aeolian
ii°	Em7♭5	Half-diminished pre-dominant	Same as Aeolian
v (minor)	Am7	Weak dominant (no leading tone)	Same as Aeolian

The Im7 → IV move is the Dorian sound. Play Dm7 to G major and you've stated the mode. That exact move appears in "So What," "Oye Como Va," "Scarborough Fair," and countless jazz standards and modal pieces.

Dorian vs. Aeolian

Both are minor modes. The only difference is the 6th degree:

A Dorian:  A B C D E F# G    ← F# (major 6th)  → IV chord = D major
A Aeolian: A B C D E F  G    ← F  (minor 6th)  → IV chord = Dm (minor)

Dorian:  Im7 — IV (major) — ♭VII
Aeolian: Im7 — iv (minor) — ♭VI — ♭VII

Dorian is warmer; Aeolian is more sorrowful.
The ♭6 in Aeolian is the note that tips it into deeper sadness.

Dorian Over a ii Chord in Jazz

In a ii-V-I progression in C major (Dm7-G7-Cmaj7), the ii chord (Dm7) is technically D Dorian — you're playing the C major scale starting on D. The notes available are exactly the Dorian formula relative to D. This means Dorian is built into standard tonal jazz harmony, not just modal jazz. Knowing Dorian as a sound helps you be more intentional about which notes to emphasise over that Dm7 chord.

Over Dm7 in a ii-V-I in C:
  C major scale = D Dorian
  Available extensions: E (9th), G (11th), B (13th / major 6th)
  The B natural (major 6th of Dorian) is the warm Dorian colour — use it.

References

• Levine — The Jazz Theory Book
• Davis — Kind of Blue (Miles Davis, 1959) — the Dorian mode record
• jazzguitar.be — Dorian Mode ↗