I noticed a thread going around about this question. They were talking about having a professional singer sing "O Divine Redeemer" by Charles Gounod for Stake Conference. There was an opinion that it was too long and too dramatic for use in that service even though it was expressly requested by the Stake President.
Years ago, I sang that piece at least once a year for some worship service or another. Always by request. I think nowadays that the "public" is used to very simple Christian "pop" songs that don't take too much preparation or ability to perform. On the other hand, "O Divine Redeemer" takes a lot of skill and musicianship not to mention a voice with an expanded range to be able to sing it well. If done well, it is beautiful and powerful. If done poorly, it is very painful to listen to.
Yes, that piece is dramatic and yes it is over 3:00 minutes long. Yet, if it is sung well, it is a masterful sermon and testimony served with gorgeous music! Too bad that we have fewer and fewer trained singers and accompanists who could pull off a good performance of such a magnificent piece.
As far as it being too dramatic for Conference goes, it doesn't seem any more dramatic than singing "Master the Tempest is Raging," "I Stand All Amazed," or "I Know that My Redeemer Lives."
As far as it being too long? It isn't longer than singing "A Poor Wayfaring Man of Grief" -- all 7 verses, or even shortened to only 4 verses.
I for one, would rather hear a beautiful rendition of "O Divine Redeemer" than any number of the Christian "pop" songs we hear so often, usually done poorly.