EWTN Catholic Q&A
Question from Larry Kolaczkowski on 01-18-2014:

During the Christmas season our parish sings "Angels We Have Heard On High". The chorus, which we sing in Latin (Gloria in Excelsis Deo) has caused some disagreement among some parishioners. A majority of the congregation, including our choir director pronounces it as "Gloria in Ex- shell-sis Deo". When I was a kid the mass was all in Latin, and we were always taught to pronounce it "In Ex-sell-sis Deo". Which is the correct Latin pronunciation?

Answer by Richard Geraghty on 01-30-2014:

Dear Larry,

It makes no difference. Go with the choir director' pronunciation, which is equally traditional.

Dr. Geraghty