Opera

 I've decided opera is a different thing from what I'm studying. Opera belongs more to adaptation studies, like studies of movies based on novels or plays. The same for ballets. I know nothing about dance. Ballets and operas could be the subject of a whole 'nother book, which someone else should write.  

I don't even know where to get the scores for 2 operas based on Yerma. I don't find all the ballets based on Perlimplín all that interesting to me.