Copenhagen 1943

Just been to a performance of Porgy and Bess and in the programme notes I read that the European premiere was given in Nazi-occupied Copenhagen in 1943.  "Even more extraordinary is how an opera about black people by a Jewish composer got to be put on there at all."  Indeed, and I wish they had gone on to elaborate on that, but that's all they said.

I've just googled this and found it was put on by the Danish Royal Opera and was shut down by the gestapo after 22 performance who threatened to blow up the opera house, and "It Ain't Necessarily So" was broadcast by the Danish resistance, but I'd like to know the rest of the story.