What they are
A mode is the major scale started from a different degree, with that degree as the tonal center. With the white notes alone:
- Ionian C D E F G A B: the major scale.
- Dorian D E F G A B C: minor with a major 6th (B). A “bright” minor sound, funky.
- Phrygian E F G A B C D: minor with a minor 2nd (F). Dark, Spanish-sounding, typical of drill and metal.
- Lydian F G A B C D E: major with an augmented 4th (B). Dreamy, cinematic.
- Mixolydian G A B C D E F: major with a minor 7th (F). Rock, blues, funk.
- Aeolian A B C D E F G: the natural minor.
- Locrian B C D E F G A: with a diminished 5th. Unstable, rare as a center.
Parallel method (all on C)
To hear the color it is best to compare them on the same tonic: C Dorian = C D Eb F G A Bb; C Phrygian = C Db Eb F G Ab Bb; C Lydian = C D E F# G A B; C Mixolydian = C D E F G A Bb. The characteristic note is the one that distinguishes the mode from the nearest major or minor.
Chords that define the mode
- Dorian: i–IV (Am–D in A Dorian; the D major contains F#, the major 6th).
- Phrygian: i–bII (Am–Bb in A Phrygian).
- Lydian: I–II (C–D in C Lydian; the D contains F#).
- Mixolydian: I–bVII–IV (C–Bb–F).
- Aeolian: i–bVI–bVII (Am–F–G).
To preserve the mode, avoid the V7–I cadence of major/minor, which would bring the ear back to Ionian or Aeolian.
Real example
“Oye Como Va” (Santana, 1970) alternates Am7 and D7 (or D9): the D major brings the F#, so the piece is in A Dorian. The theme of “The Simpsons” is a famous example of Lydian; “Norwegian Wood” by the Beatles uses Mixolydian. Bernstein devoted an entire episode to the modes in the Young People's Concerts (“What Is a Mode?”).