VI. Jazz
77
Megan Lavengood
Key Takeaways
This chapter presents two ways of adding new harmonies to an existing chord progression.
- An applied ii chord, as in the ii–V–I schema, can be used to embellish a dominant-quality chord. In other words, preceding a dominant-quality chord with the mi7 or ∅7 chord a fifth above it creates the effect of a ii–V.
- Common-tone diminished seventh chords (CTo7) create neighboring motion in all voices that embellish a chord. The root of the chord of resolution is always shared as a member of the CTo7—hence the term “common tone.” (Note: See this chapter for more information on CTo7 chords in Western classical music.)
Jazz performers often aim to add their own twist to existing jazz standards. One way of doing this is to add new chords that embellish existing chords in the progression. This chapter explores two ways that performers improvise by embellishing harmonies in jazz.
This chapter will use the opening few bars of “Mood Indigo” by Duke Ellington (1930) as a backdrop and add embellishing chords to it. If you take a moment to familiarize yourself with the tune, the following discussions will make more sense. Listen to Louis Armstrong’s interpretation of this song, embedded below, while following the chords of the first few bars, given here.
https://musescore.com/user/32728834/scores/10006141/embed
Embellishing Applied Chords
Applied V7
Any chord in a progression can be embellished by preceding it with an applied dominant chord. takes the surprising G♭ chord of measure 7, divides it in half, and replaces the first half note of the chord with its applied V7 chord. In principle, this can be done with any chord in the progression.[1]
https://musescore.com/user/32728834/scores/5719733/embed
Applied ii
The chapter on ii–V–I discusses the use of applied ii–V–Is, i.e., ii–V–I progressions that occur in keys other than the tonic key. Many jazz tunes have these applied ii–Vs built in, but a performer could add their own as well. A dominant chord can often be embellished by adding its ii chord before it, transforming it into a ii–V schema.
“Mood Indigo” by Duke Ellington begins with the progression B♭–C7–Cmi7–F7–B♭. That first C7 could be embellished by adding a Gmi7 before it, creating a temporary ii–V that then proceeds to another ii–V. Rhythmically, this means cutting the duration of the C7 into two halves and replacing the first half with the applied ii chord. The result is the progression in
below.https://musescore.com/user/32728834/scores/5719690/embed
Common-Tone Diminished Seventh Chords (CTo7)
The common-tone diminished seventh chord (hereafter CTo7) is a voice-leading chord, which means that the chord is not based on a particular scale degree like most other harmonies, but rather the result of more basic embellishing patterns. In this case, the embellishing motion is the neighbor motion. To create a CTo7, the root of the chord being embellished is kept as a common tone (hence the name), and all other voices m