Here is an interesting article about racism in opera. It's from last summer.
It is important to realize that events in the past cannot be shoehorned into the 21st century. People in the past did not think as we do. Opera is an art form from the past. If we removed every distasteful thing we didn't like, it's difficult to see what would be left. We love it anyway.
Aida is sometimes played by a white woman. She was probably chosen because her voice suited the role. I recently read a tirade by a young woman who bought her tickets thinking a black woman would sing, and instead it was a white woman. She became furious. The originally cast singer was ill. As I have pointed out elsewhere, there is no reason to suppose that the Egyptians in the story were not themselves also black. The story is about national identity and not race. Think Romans and Gauls, as in Norma. Or French and Germans.
Otello is usually played by a white man because we are lucky to be able to find anyone at all who can sing Otello. If you know a black man who qualifies, will you please suggest him. The story is about race, so Otello is done in black-face, a phenomenon that has cultural significance only in the United States.
I read in one of the comments that the owners of Porgy and Bess are the ones who insist that it be sung only by black singers. I will stop blaming Gockley.
At the beginning opera was written on subjects based in Greek mythology. Are they then parodies of Greek culture that patriotic Greeks should complain loudly about?
Every theatrical work is a parody of one kind or another. The only issue is does this parody still speak to us?
I object to Butterfly and refuse to go to it because of the objectionable portrayal of the white man in the story. He is simply profoundly disgusting, a racial parody of the worst possible sort. By contrast Cio Cio San is complex and fascinating.
This is just my personal opinion, but I think insisting that characters can only be played by members of the represented race is itself racist. I prefer that singers are chosen for their singing and acting.
Eric Owens is singing all around these days, recently in Flying Dutchman. He was recently announced for Philip II in Don Carlo. He is a great singer and should sing everything he can.
At home I am not allowed to discuss this subject.
22 minutes ago