An excellent article by my friend Dr Michael Haas may interest many in this forum, especially those studying and researching composers of the first 3 decades of the 20th century who were persecuted and eventually went into exile including Schreker, Gal, Braunfels, Zeisl and Korngold. This is a useful survey with many historiographical inisghts.
https://forbiddenmusic.org/2020/10/19/jewish-musical-identity-and-the-crisis-of-exile/
... and before that, Michael had already written a fabulous 360-page book on this theme:
https://yalebooks.yale.edu/book/9780300205350/forbidden-music
I skimmed that book and recall being somewhat taken aback at his attributing Robert Fuchs' opera Die Königsbraut to Josef Fuchs. (Just because it's not central to one's argument doesn't mean one shouldn't be careful.)
All books contain occasional mistakes, eschiss-1 :-)
In my opinion, Michael's book is greatly instructive, also because it examines the subject in close (and detailed) context with the political situation. So far I've never read a musical monography with such a clear insight on Europe's politics of that time.