Teaching the modes of the diatonic scale: another tack

I have made several attempts to explain the concept of musical modes to people unfamiliar with music theory. (This is not some arcane concept from medieval church music: folk, jazz, rock, pop, and even metal often delve into modes.) The video above, by “Signals Music Studio”, takes another tack and keeps it accessible.

If the Greek names are confusing to you, it may be helpful to just number them by the diatonic step that is the tonic (“home note”). [I personally used to number them by the number of flats they had in C, which is equivalent to numbering along the circle of fifths rather than by diatonic steps.] Thus you get:

1. natural major mode (Ionian, classical major scale)
2. “minor-lite” mode (Dorian)
3. “uber-minor” mode (Phrygian)
4. “uber-major” mode (Lydian)
5. “major-lite” mode (Mixolydian, folk major scale, bagpipe scale)
6. natural minor (Aeolian, modal minor scale, descending melodic minor scale)
7. diminished (Locrian; not really used much because its tonic chord doesn’t even have a perfect fifth)

The Signals guy picks out “the characteristic note” of each: the note most keen to ‘resolve’, so to speak. That would be (assuming the tonic is C below):

1. major/Ionian: the lead tone (B) which is a major seventh that wants to resolve to the octave.
2. minor-lite/Dorian: the major sixth (A) which sets it apart from natural minor.
3. uber-minor/Phrygian: the flattened second (Db)
4. uber-major/Lydian: the augmented fourth (F#)
5. major-lite/Mixolydian: the flattened seventh (Bb)
6. natural minor: the flattened sixth (Ab)
7. Locrian: the flattened fifth (Gb)

Note that, when improvising and unsure which mode the other players are in, the ‘poor man’s substitute’ of a minor pentatonic will work  with all three modes 2,3,6 (Dorian, Phrygian, natural minor), while a major pentatonic can fit all three modes 1,4,5 (natural major, Lydian, and Mixolydian)

Of course, the ‘flavor’ each mode has is intimately connected with the chords it implies. If you go by the major/minor character of the “three main chords” I (tonic), IV (subdominant), and V (dominant):

1. natural major: C, F, G major triads
2. Dorian: Cm, F, Gm.   Note that both tonic (I) and dominant (V) are minor, while the subdominant (IV) is major. Note also the major chords on the flattened seventh and third: countless rock riffs exploit cadences like Cm-Bb-Eb-Cm or Cm-Bb-F-Eb
3. Phrygian: Cm, Fm, Gm. Note the characteristic major chord on the flattened second: cadences like Cm-Db just write themselves
4. Lydian: C, F#dim, G. The most archetypical cadence in Lydian is however I-II
5. Mixolydian: C, F, Gm. The major chord on the flattened seventh step just begs to be used, though, and you naturally get cadences like (in E) E-D-A/C# (AC/DC’s “Back In Black”)  or (in G) G-C-F-C (Rolling Stones, “Honky Tonk Woman”).
6. Aeolian: like Phrygian, all three of the I-IV-V chords are minor. But here the IIIb, VIb, and VIIb are the major chords, so cadences like C-Bb-Ab follow naturall

Note that in common practice harmony as practiced in Western classical music, the minor chord on the dominant was more or less verboten, which led to the development of a melodic minor scale (often explained as ‘sixth and seventh not flattened when the melody ascends’) such that the dominant chord could be major. Throughout the Renaissance and Baroque periods, it was still considered dissonant to end a piece on a major chord, so the final tonic chord of a piece would be turned major (a “Picardian third” as this was then known).