I know it's Christmas has passed but I came across this a little earlier and have watched it a number of times. I went to a Catholic elementary school and can remember the joy of singing Christmas songs in preparation for Christmas Mass. In the weeks leading up to Christmas, sometimes our recess would be spent in the church singing songs and being coached by the nuns.
We had a nun who would encourage us to lift our voices to God and be sure our priests could hear us in the rectory, she was cool for a nun. I could always tell when we were singing well and our voices were carrying by the slight grin and sometimes full smiles the nuns would have on their faces.
When I saw this and heard this little girl's voice and the choir behind her it brought back all those memories. I hope you all enjoy it as much as I did even though we are past Christmas.
https://www.youtube.com/watch?v=RvUMDp-snTI