Most difficult repertoires to get into ?
As a non Western singer living in Europe since nearly ten years, I've studied a handful of repertoires (even non operatic music) as well as their contexts. As musicians, no doubt we're supposed to expose ourselves to lots of styles and colours. However, the libretti do play huge part in making us truly invested in the work.
This is why when the plot implicates either:
- Some extremely specific lore that you're supposed to comprehend before e.g. Greco-roman mythology/story: Alessandro, Tiridate, Tigrane
- Historical politics: Don Carlos, Rienzi (generally grand operas, with tons of decors and people on stage)
- Opérettes that sometimes have the above (I've sung in several Offenbach works as a chorister or even soloist and as a French speaker I mostly just couldn't careless about the plot, too many references I don't get)
- Very dated language, like sei/settecento italian stuffs (Monteverdi --> Mozart and even later), difficult for me as an Italian speaker.
You sometimes can find all of these together, which tbh makes for understanding what you're listening and/or watching quite frustrating, not to mention the weird abrupt endings that sometimes make no sense. At some point, whether it be a comic or a serious work, I just listen to and enjoy the singing and the music. If I ever do listen/sing them again for pleasure, well it'll always be more for the music than the plot, if I ever do manage to understand it at all.
As for the things that are actually simple to get into. I'd say French and Italian baroque operas that often have "dumbed down" plots, either a kingdom being a simple set up for love intrigues, with war betweem two opposing sides. That or just straight up a pastoral with tons of Amintas or Fillis being unfaithful to each other. Then there are the verismo and verismo-ish operas (French), which tend to have a much more narrow setting and shorter lengths: Pagliacci, Cavalleria rusticana or if there are many things, it doesn't matter if you don't take them into account, because love/human relations are the main thing: Onegin, Carmen.