Concert Hall location
I tried to upload this via the updates system here but clearly the IMDB experts don't agree with me, even though I interviewed Bette Davis about the film, for my biography of its composer, Erich Wolfgang Korngold.
It may interest you all to know that the concert hall where the Hollenius cello concerto is rehearsed and performed is actually the theatre in San Francisco where the famous "understudy" confrontation scene in ALL ABOUT EVE was also filmed, 4 years later.
If you want more details, I'll post.