Embellishments and Substitutions.
Jazz harmony is considerably enriched by the deployment of 'embellishments' and 'substitutions'. Embellishments are added chords or scale fragments which provide continuity in moving from one chord to another. This example illustrates a movement from Ab to EbMaj7.
A 'substitution' is a chord or a chord sequence which is used in place of the written chord. A common substitution replaces a dominant V chord with a II - V sequence. Hence in SATIN DOLL the sequence
A further substitution could replace the II chords with half diminished chords.
A further 'embellishment/substitution' could be employed using a descending bass-note in the opening four bars.
Note that D-7/Db implies and Dm7 chord played over a Db in the bass.
In the last two bars 13ths could be added.
Hence with some imaginative use of substitutions and embellishments the harmonic sequence is enriched.
As a general rule, a V chord can usually be replaced with a II - V pair.
The circle of keys is also a useful device for substitutions.
The student is strongly advised to study and remember this sequence in order to create the automatic facility necessary to jazz performance. Practise the sequence in both hands (if you are a pianist), beginning at different points of the circle.
Normally the movement through the circle of keys is counter-clockwise. In other words;
E(III) tends to move to A(VI)
A(VI) tends to move to D(II)
D(II) tends to move to G(V)
G(V) tends to move to C(I) etc.
In the example shown above it is understood that the minor seventh intervals may imply dominant chords, or minor 7th. chords, or half-diminished chords. The major thirds imply dominant chords only.
The student should practise the the minor seventh - major third pattern from different starting points on the circle.
An example of the use of the substitution of Bm7, E7, Am7, D7 in place of D7 is seen in Duke Ellington's 'In A Sentimental Mood'.
Listen to this beautiful arrangement of the Duke Ellington classic
and follow the manuscript or play along with it. (click on manuscript to listen)
ALTERNATE CIRCLE OF KEYS An alternative harmonic pattern may be derived from the circle of keys by moving between the circumference series (C-F-Bb etc) and their diagonals (C-Gb, F-B, Bb-e, etc).
The following example illustrates this (alternate) pattern.
This chord sequence may also be practised as in the previous circle exercise.
A good example of how the alternate circle pattern may be used is found in
'I Can't Get Started' by Vernon Duke.
There are many other substitutions and embellishments which are used in Jazz. To list them all would be impossible and not desirable, since part of the joy of Jazz is discovering for oneself new and old variations which are used by the great exponents of the creative art.