Catherder, I completely get what you said about
Mary, Did You Know? striking you in the heart. It's a powerful song. I sing it at church at least once in December in hope that it will touch as many people as possible.
Oncefallen and didymos, I have being singing most of my life and I have to say that standing in a choir singing the Hallelujah Chorus is one of the most impactful things I've ever done musically. It absolutely does remind you of what it might have sounded like the night the angels sang His glory.