It was habit in the nineteenth and early twentieth century to present operas, whatever their original language, in the language of the host country. Playbills of the past are filled with references toWagner's Il Sigfrido, or Mozart’s Il Fluto Magico, or Figaro's Hochzeit. The idea was, of course, to fill the seats. This is especially important in comedy, because what was the point if nobody got the jokes!