Download Tonal Harmony Chapter 15 Other Diatonic Seventh Chords

Chapter Fifteen
Other Diatonic Seventh Chords
Introduction
 Most commonly encountered seventh chords built on 5th, 2nd and 7th degree
 The other diatonic built on 1st, 3rd, 4th, and 6th degree are much less commonly used in traditional
tonal music
 One context in which they are relatively common is in circle-of-fifths sequences
The IV7 Chord
 Similar to the subdominant triad, subdominant seventh moves to V (or iio6)
 Often passing through some form of the ii chord on the way
 The resolution to ii7 (possibly inverted) is easy to handle, only the 7th needs to move
 When the iv7 moves directly to V, //5ths may result if the 7th of the chord is placed above the 3rd,
Correct by:
o Use of Candential 64 OR
o Doubling the 5th of the V chord
 Example 15-4 features a circle-of-fifths sequence using seventh chords. A metric device which is
known as hemiola (e.g. meter is in 34 but sound as if they are in 24), has been in used for many
centures
 The subdominant seventh in minor with a raise 6th is a major-minor seventh chord, but it DOES
NOT have a dominant function (raised 6th going to leading 7th  tonic)
The VI7 Chord
 The submediant seventh is found in three forms
o vi7
o VIM7
o #viø7
7
 vi or VIM7 typically move toward V, usually passing through subdominant or supertonic chords,
or both on the way
 It is relatively easy to progress to IV
o In minor, when the root of the submediant seventh moves up by step to rasied 7th, the 6th
must be raised to avoid an interval of +2. The chord that results when 6th is raised is a half
diminished seventh: #viø7
ø7
 #vi usually serves as a passing chord between two chords of dominant function (V or viio)
 #viø7 move most smoothly to the otherwise unusual root position viio
 #viø7 can move directly to V65 instead of viio if 1st leaps to 5th
The I7 Chord
 In major key, the tonic seventh chord in its diatonic form is a M7 chord
 In minor key, it is a m7 chord. The minor-major seventh chord in minor, possible but quite rare
(used freely in jazz)
 Adding a 7th deprives it of tonal stability, and no longer serves as a harmonic goal or resting
place.
 Demand resolution which tends to move to IV or sometimes to a ii or vi
 The chord of resolution MUST be one that contain the 6th degree (7th can resolve to 6th)
 The 7th of the chord is frequently analyzed as an NCT (passing tone)
The III6 Chord
 In major key, the diatonic median seventh chord is a iii7
 In minor key, it is a IIIM7
 The iii7 usually progresses to a VI(7), but it may also be followed by a IV chord
Seventh Chords and the Circle-of-Fifths Sequence
 Usual harmonic functions of most diatonic chords are closely related to the circle-of-fifths
sequence
 One of the most commonly used sequential patterns
(iv7 – VII7 – IIIM7 – VIM7 - iiø7 – V7 – i)
 If the chord used in a circle-of-fifths sequence, follow these rules about voice leading,
o If the seventh chords are in root position in four-part texture, COMPLETE chords will
alternate with incomplete chord
o If the seventh chords are inverted in a four-part texture, either 65 chords will alternate
with 42 chords, or 43 chords will alternate with root position chords
o Except the bass, every voice either stays the SAME or move down BY STEP
 In three-part textures, circle of fifths sequence will usually be in root position. Principle about 4part texture holds true