The Diatonic Modes

You’ll be able to

Derive the seven diatonic modes as rotations of the major scale
Identify each mode’s characteristic altered scale degree
Recognize modes by their brightness and signature intervals

Modes as rotations of the major scale

The seven diatonic modes are the scales you get by starting the major scale on each of its seven degrees, using the same notes but a new tonic. From the C major collection: C Ionian (the major scale itself), D Dorian, E Phrygian, F Lydian, G Mixolydian, A Aeolian (the natural minor scale), and B Locrian. Each has a distinct pattern of whole and half steps and therefore its own color, even though they share the same seven pitches.

Characteristic notes

The quickest way to hear a mode is by the one degree that differs from the parallel major or minor. Among the minor-type modes (with a lowered third): Dorian is natural minor with a raised 6th; Phrygian is natural minor with a lowered 2nd; Aeolian is natural minor itself; Locrian adds a lowered 2nd and lowered 5th. Among the major-type modes (with a major third): Lydian is major with a raised 4th; Mixolydian is major with a lowered 7th; Ionian is plain major.

Brightness from Lydian to Locrian

Ordering the modes from brightest to darkest — Lydian, Ionian, Mixolydian, Dorian, Aeolian, Phrygian, Locrian — each step lowers one scale degree. Lydian’s raised 4th makes it the most luminous; Locrian’s lowered 2nd and 5th (its unstable diminished tonic triad) make it the darkest and rarest. This gradient helps you place a mode by ear: the more lowered degrees, the darker the sound.

Deriving a mode

mode on degree n = major scale starting from its nth note · D Dorian = C-major notes from D

Dorian = raised 6th · Phrygian = lowered 2nd · Lydian = raised 4th · Mixolydian = lowered 7th · Locrian = lowered 2nd and 5th.

Worked example

Build D Dorian and identify the characteristic note that distinguishes it from D natural minor.

1.D Dorian uses the notes of C major starting on D: D E F G A B C D.
2.Compare to D natural minor: D E F G A B♭ C D.
3.The difference is the sixth degree: Dorian has B♮ where natural minor has B♭.
4.So D Dorian is a minor-type mode distinguished by its raised sixth degree.

Answer: D Dorian = D E F G A B C D. Its characteristic note is the raised 6th (B♮ instead of the B♭ of D natural minor).

Checkpoint

Which mode is a major scale with a lowered seventh degree, giving it a "bluesy," relaxed dominant sound?

Tip

Sort modes into two families first: if the third above the tonic is major, it is Ionian, Lydian, or Mixolydian; if minor, it is Dorian, Phrygian, Aeolian, or Locrian. Then pin down the single characteristic degree (raised 4th, lowered 7th, raised 6th, lowered 2nd, and so on).

Checkpoint

E natural minor is spelled E F♯ G A B C D. E Phrygian differs from it by which altered scale degree?

On the exam

Identify a mode by its tonic and its one signature interval, not by key signature alone — D Dorian and C major share the same notes but sound different because D is the tonic. Naming the characteristic degree (e.g. "Dorian: raised 6") is what secures the point on a modal analysis question.

Answer the 2 checkpoints as you read.