I was helping some of the high schoolers pronounce the Latin text -- then they corrected my pronunciation. We were singing the phrase, "Agnus Dei," which I pronounce ahg-noose day-ee (more or less); however, the pronunciation guide, which I hadn't even noticed, said to pronounce it ahn-yoos day-ee.
Now, I realize that singers do all kinds of things to Latin -- and have done, for centuries -- as a way of making difficult sounds come out better. So for all I know, the pronunciation ahn-yoos is more or less standard among church choirs. But I can't see Cicero pronouncing it that way. And, trained as I was in Classical Latin, it would comfort me to know that I'm doing it right.
So: what was the pronunciation of "agnus" in Classical Latin? And assuming that the ancient pronunciation would be ahg-noose, then did medieval choirs in the Catholic Church pronounce it ahn-yoos, or is that a modern attempt to make it sound prettier?