Thursday, March 21, 2019

Videos about "other" diatonic seventh chords (Chapter 15)

I made a two-part video series for Chapter 15 (part 1, part 2). Please watch these for Tuesday, March 27. We may have a mini-quiz.


Notes:

For ALL diatonic seventh chords
  • Have the same function as corresponding triads
  • Chordal 7th must resolve down by step—STRICT
  • Chordal 7th must be prepared
    • Common tone—looks like suspensions
    • Stepwise motion—looks like PT or NN
    • Jump up—looks like appoggiatura
  • Write seventh chords complete, ESPECIALLY in inversion (=no doubling)

Leading-tone seventh chord
  • Ti-re-fa-la (in major) – ø7
  • Ti-re-fa-le (in minor or major) – º7
  • Stepwise motion
  • Tonic prolongation
  • Voice leading
    • Ti --> do
    • Fa --> mi (me)
    • La (le) --> SOL
    • Re --> Do or mi (me)*

Supertonic seventh chord
  • Predominant
  • “Do” is chordal seventh
  • Combines ii and IV (iiº and iv in minor)
  • Quite commonly used

Subdominant seventh chord
  • Predominant
  • (Major key) Fa-la-do-Mi … IV7 (chord quality MM7)
  • (Minor key) Fa-le-do-me … iv7 (chord quality mm7)
  • Scale degree ^3 (mi/me) is chordal seventh
  • An alternate harmonization of ^3-^2-^1


Thursday, March 14, 2019

New videos for chapter 14 (the submediant)

Video, part 1.
Video, part 2.


There's lots of information in chapter 14. We won't have time to cover it all in depth. Here are the topics:
  • The mediant triad
  • The submediant triad
  • The subtonic triad
  • Harmonizing a melody with keyboard figuration

Here is the most vital information for each topic:

The mediant triad
  • Spelled "mi-sol-ti" (or "me-sol-te" in a minor key)
  • Functions similarly whether in a major or minor key, though perhaps somewhat more commonly used in minor
  • Contains two common tones with tonic (mi/sol), and therefore may be used as a tonic substitute in some instances. (See p. 331, ending sentence of first full paragraph.)
  • Almost always used in root position (meaning that when it's used as a tonic substitute, it's used in place of a I6 chord). See "Im Frühling," m. 1, beat 2 on handout.
  • A good way to harmonize the descending leading tone.
  • The apparent mediant (discussed on page 336) is really a dominant; we have already seen this in the Schumann "Folk Song" example (m. 8 beat 2).

The submediant triad
  • Spelled "la-do-mi" (or "le-do-me" in a minor key)
  •  Functions similarly whether in a major or minor key
  • Again, usually used in root position (except in a few particular circumstances).
  • Also contains two common tones with tonic (do/mi), and therefore may also be used as a tonic substitute.
  • As a tonic substitute, the submediant can serve as the resolution of V or V7. We have seen this already in the deceptive cadence; it can also happen within a phrase.
  • Submediant can also function as a predominant, or pre-predominant. See the discussion on page 334 with regard to the ambiguous function
  • Tonic chord with 5-6 motion above the bass (apparent "vi6")
  • Mediant sometimes progresses to the submediant, as in our descending fifths progression.
Note: both the mediant and submediant are considered "secondary" triads in a key. That is, they are less important than the "primary" triads--tonic, dominant, and subdominant. I think this is in part because they tend to have a kind of "mixed" feel. Although each has two common tones with tonic, each also has a common tone with one of the other primary triads: mediant has "ti" in common with V, and submediant has "la" in common with IV.

Mediant/submediant examples:






The subtonic triad
  • Major triad, spelled "te-re-fa" and occurs only in minor keys
  • Most typical use is to precede the mediant, and act as if it were its dominant (V/III, pronounced "five of three")
  • Occasionally used as a dominant substitute. When this occurs, it's typically in modal music, either late Renaissance/very early Baroque (that is, pre-common practice music; see Schein Example 14.11b, p. 339) or pop styles, for example Black Sabbath, "Paranoid" (in E aeolian) or The Grateful Dead, "Fire on the Mountain" (in B mixolydian). In both the latter examples, tonic alternates with VII throughout. Feel free to present another example you're familiar with for a mini-lesson!
  • The Folia and Romanesca patterns are interesting, but not that commonly used.


Harmonizing a melody with keyboard figuration
See separate post