I pointed this out on another thread ....one of the members of this forum pointed me to this interesting history book.
"Composers of the Nazi Era: Eight Portraits 1st Edition" by Michael H. Kater
https://www.amazon.com/gp/product/0195099249/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=AL05K0SB8PFZQInteresting account of the following composers:
Egk
Hindemith
Weill
Hartmann
Orff
Pfitzner
Schoenberg
Strauss
my thought on Paul von Klenau was probably just an opportunist... but was a member of the Nazi Party.
Kater seems to be the specialist in this era, but I would have thought that at least half of those figures were well gone over in other sources.