This month's lesson is about using an umbrella (using one scale or
structure) to reharmonize/substitute over a ii-7 V7 I. It's an example
of how what seem like really strange note choices are in fact firmly
grounded in functional harmony. If you know what to listen for. Plus,
there is use of chromatic approach notes at one point in each example
In the first example,
the entire G-7/C7 portion of the progression is covered by using a
Gb7+4 (Tritone) substitution, which resolves by half step to the third
of the Fmaj chord. It is the clear resolution that makes the substitution
work. Otherwise it might sound aimless and confused.
At first
glance, the note choices over G-7 don't make sense. When analyzed
in terms of the substitution however, the Gb7 is outlined in classic
hard bop fashion, with the seventh degree of the Gb7+4
scale approached from a half step above/half step below. The fact
that there are "wrong" notes over the chord is mitigated
by the cohesiveness of the line and the ultimate resolution.
The
next example is the same line transposed up a minor third, and resolves
to the fifth of F Maj. This works on the same idea found in the Diminished
Scale — that structures within the scale can be transposed
in minor thirds and still function as the underlying dominant chord.
Here the A7+4 scale is used as the umbrella,
with the same chromatic approach to the seventh degree. The "wrong"
notes are again taken care of by the internal logic of the line.
