5. Adjacent Chromatic Modes
In each of the two Chromatic Modes,
- the Chromatic Major Mode (Mode 3), and
- the Chromatic Minor Mode (Mode 4),
we had a DOMINANT/TONIC swing
which was composed of 2 strong Dominant-shape chords,
and in which each chord could be the DOMINANT of the other.
It is therefore possible for each member of this swing
to be a TONIC chord which uses the other as its DOMINANT.
We have arbitrarily chosen the E7 - Am6 swing (from mode 4)
but we could just as well
have chosen the Fm6 - C7 swing (from mode 3).
The two chords of this swing are adjacent TONIC chords,
but they belong to Windows that are 4 notches apart
one (that of A minor) in the natural Window, and
the other (that of E major) in the 4-sharp Window.
Only the E7 - Am6 swing is common to both Windows,
completely at the top of one and at the bottom of the other.
Now we know, from the Diatonic Modes (1 and 2)
that we can travel back and forth in the same Window
between the two relative modes, major and minor.
between A minor and C major in the natural Window, and
between E major and C# minor in the 4-sharp Window.
In other words, all the way from C major to C# minor,
using the Am-E swing as a pivot.
The Key of E major has
a chromatic mode relationship with the Key of A minor and
a diatonic mode relationship with the Key of C# minor.
The Key of A minor has
a chromatic mode relationship with the Key of E major and
a diatonic mode relationship with the Key of C major.