"The tritone part is that the flat 2nd scale degree is a tritone interval from 5th scale degree."

oh.
well that's relatively straight forward
(thanks)

however/incidentally...it's interesting to me:
as you elaborated...
you started citing stuff that I have some intellectual understanding of...
but have yet to internalize it into practically knowledge
so a kind of stacking obscurity occurred the more I read.

thus theoretically I have a vague idea of what Dave was referring;
yet practically I remain in the dark;
and just appreciate the perspective here:
things to get into when I get there.