Like the age-old "chicken or the egg" argument, it's interesting but unimportant as to which came first.
For the improviser, however, it's essential that he or she becomes fluent with both concepts and can readily visualize and execute each in a creative situation.
"Vertical Structures", focuses on and explores some of the more common scale systems and modes (Lydian, Dorian, Melodic Minor, Harmonic Minor & Major, as well as the half tone/ whole tone Diminished Scale) and presents them (in 12 keys) as selected, extended 13th chord arpeggios and sequences, as well as diatonic 4th stacks.