Latin!

Gloria in excelsis Deo.

How many ways are there to pronounce this?  

I actually don't know the answer to that question.  Ecclesiastical Latin, German Latin, French Latin, other Latins, all the dialects of the stylized Latins... 

I think it's possible to make a decision and be clearly wrong.  But I also think there are multiple options that could be just fine.  I don't want to say the "right" choice, because what does that mean?  Let me give an example.

My students, as a part of their choir auditions, will prepare the first two (short) sections of the "Gloria" from Haydn's Harmoniemesse.  If I were to ask my students to prepare this using French Latin, that likely could be considered a wrong choice.  Or at best, a bad choice.  Now, if I were to ask them to prepare the piece using German Latin, there is no longer a clear line that this is wrong (or bad).  There have been many people who choose to have their choirs sing German Latin on this piece.  However, due to the information I have at my disposal, I'd likely choose Ecclesiastical Latin.  I wouldn't call this the "right" choice, but I think it is a "good" one.  

And why all careful language about "right" and "good" and "correct" and "bad" and "wrong"?  (Sorry, I know that the question mark is supposed to be inside the parenthesis, but it just looks wrong).  Because even IF you could say the HIP (Historically Informed Practice) is the "correct" way to do something, the issue is that we don't truly know how any choir pronounced it during the time period.  So, let's pretend we came across an authentic Haydn-document that said, "Haydn's Harmoniemesse rehearsal 1: Tell Choir we are singing in German Latin." Even this document would not be clear, because it may still include stylistic nuances we do not know.  

The larger point, which can be applied to many choices, is this: what is "fashionable" changes.  It was, at one point, really cool to sing most things by German composers in German Latin.  We know now that likely didn't happen, but we can't be sure there weren't some German-language influences.  I would never scoff at someone who made a choice to sing a Mozart work in German Latin.  I may or may not make that choice myself, but it doesn't require any sort of pretentious response from me.  The same idea can be applied to tempo, phrasing, or a variety of other musical ideas.  Thoughtful choices are all that are required for me to be engaged with the music.