Thanks everyone.
Just to make sure there's no confusion: the woman playing the church organ in the middle of the video without sound is my colleague (we are two female organists in our parish as we have three churches and sometimes two services simulaneously).
Link to the complete service:
https://youtu.be/Go1K3tW9JG0
and to "Go tell it on the mountain" as an uninterrupted version:
https://youtu.be/3Fdr76l7bFc