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JAZZ
THEORY (BeBop Drills)
The Jazz Sub-Dominant
Chord - II-7
Throughout the centuries
musicians have organized harmonic changes into three basic categories. Chords of
rest and resolution are called tonic chords, and the Imaj7
chord we have been studying functions this way in Bebop. Chords of tension
are chords which create harmonic momentum through dissonance and placement
within a progression, and are called dominant chords. The chord we will examine
here falls into the middle ground, which identifies chords of movement as
sub-dominant.
Bebop’s principle
sub-dominant chord is the II-7, the minor seventh chord built from the second
degree of a major scale. The example we will use is C-7, II-7 in the key of Bb
major. In many cases the extensions of a chord must
be altered to fit the function of the chord with 'allowable' tensions.
II-7 allows us to extend naturally through the key. The chord tones C - Eb - G -
Bb extend to the tensions D - F - A [9 - 11 - 13], all diatonic to Bb.
To perform the drills,
first fix the tonal center of the chord [not the key] is your consciousness by
playing or singing the root (C in our example). Those who can should continue to
sound the root for the duration of the drill for that chord. Next find the
lowest possible chord tone or tension and ascend, as in 1-b3-5-b7-9-11-13-1 etc.
(C - Eb - G - Bb - D - F - A - C - etc., for C-7). *Remember
that chord formulas are in comparison to parallel major scales, so even though
the chord C-7 is II-7 in Bb major, the analysis, or chord formula, is in
comparison to a C major scale.* Once you have reached the highest point
possible, descend in the reverse order to your starting point. Then find the chord
tone or tension in between the first two notes you played, and ascend and
descend in the same fashion. Play each minor seventh chord this way through the
cycle of fifths [C, F, Bb, Eb, Ab, Db, F#, B, E, A, D, G]. String players should
do this exercise one string at a time, piano players use two hands in octaves.
Some confusion surrounds the relationship between chords
and scales, in regards to modes. Many would be tempted to name the scale applied
to C-7 a C Dorian scale, a mode relative to Bb major. In Bebop the difference is
critical, for modes are scales with different tonal centers than their parent
scales, which means our C-7 chord would become a I-7 chord in C Dorian, and
would be a chord of resolution, not movement. Bebop uses the system of
functional harmony discussed above exclusively, and looks for overall tonal
centers, not temporary ones. To learn to play in the Bop sound, we must hear the
chord tones and tensions in relation to the root of the chord, but we must hear
the effect of the chord in the key to which it will eventually resolve. As
always, use your ears and happy drilling! [top]
- Frank Singer ©2002
I originally learned these concepts from Charlie
Banacos, private
instructor.
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BACK
TO THEORY DEN CONTENTS
The
Language of BeBop
The
Use of Tensions 1
The
Use of Tensions 2
The
Use of Tensions 3
The Jazz
Sub-Dominant Chord - II-7
The Jazz Dominant Chord - V7
The II-7 V7 Progression - II V series
The Key of the Moment
"Watch out for
those chromatics!"
Ear Training
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eCUTS
