18 scales on 12 roots: 216 pages.
The reference: every other scale is a change to it.
The notes of a parent scale, from a new root.
Natural minor, then with the 7th, or the 6th and 7th, raised.
Played over chords rather than built into them.
One repeating step.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.