Some background on the piece - Wiki link. For what it’s worth, my teacher is strongly of opinion that the original is a Ukrainian folk song. I’ll ask him why when I see him next.
Your fellow on YouTube is throwing in an interesting tremolo intro, and adding lots of middle voice notes. Is that his own arrangement, do you know? It’s certainly not the standard that you see in the intro classical guitar books, but that isn’t surprising - not many people since Yepes play the piece straight. Liona Boyd turned it into a wholesale tremolo piece (not surprising; it’s her strongest suit.) Lots of other guitarists avoid it because it has become a little too popular.
Well, the Wiki article linked by Le Ministre de l’au-delà answers at least part of my question:
Clearly authorship is not all that clear.
I’m hoping someone will come along soon with some help re: the “adding lots of middle voice notes” bit. That’s what I’m really interested in. I’d love to play his version but my (tin) ear is not adequate to picking out what he has added.