As a voice major in my teachers always had us sing the original language unless there was some very unusual circumstance. I learned to be respectful of the original language, & have found that if I take just a little time, I can learn much more about the song, which enables me to better interpret it. I appreciate getting to see the oldest known score for Stille Nacht, which I learned (in the deutch) many years back-before Music school even-from a German American minister who explained the meaning of the lyrics. Even then as a teen, I wondered why the English version (not a translation!) was ever sung because it did not convey the meaning of the beautiful song.