Ever heard anyone singing opera in English? Of course not - opera is done mainly in Italian though I believe the French insist on it being translated into frog. Pop music on the other hand has been dominated by the Americans and to a much lesser extent by us, so its overwhelmingly in English. sSo what.
Does any of that really matter?
The ENO have, for at least 20 years to my knowledge and possibly for much longer, sung exclusively in English.
English opera has had a very mixed history, but is in rude good health today. Before they were renamed English National Opera in the 1960s, the Sadler's Wells opera company sang the world premiere of Britten's Peter Grimes, which was the first really internationally successful opera in English for 300 years or so, since Henry Purcell's day. But today you'll find ENO, the Welsh and Scottish national companies, and many of the great festival operas (notably Glyndebourne and Garsington) regularly putting on works in English translation, in addition to vast numbers of professional, semi-pro and amateur productions across the UK and North America.
Otherwise, operas tend to have been written in the language of their sponsor or librettist. Mozart, for example, was equally happy composing music for Italian (La Nozze di Figaro) librettists as he was for German (Die Zauberflöte) words. It mostly depended on who commissioned the work.
