Well, In Extremo is a German band, and German isn't a foreign language to me, but they often sing in obscure languages (Ai vis lo lop is in Occitan, Zauberspruch from the Album "Sängerkrieg" was in Estonian, Pavane is in old French, Herr Mannelig is in old swedish, Liam is in Gaelic, some other songs are in Latin, and so on).