In this Jim Greeninger clip, he plays a lot of bass changes that I’ve never heard before. Are they part of the piece, or is he adding stuff in? The intro lasts about a minute, for those in a hurry.
Also, I’ve heard this credited to Sor, but when I learned it (back in the early part of last century :)) it was “traditional” on the sheet music. Which is correct?
No clue - sorry; but thanks for sharing! He is a great player!
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.
I have no idea how to answer your question, but thanks, I’m gonna add this to the list of guitar songs to play next!
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.
I’m swamped right now - if you’re still stuck in a month, drop me a PM and I’ll see what I can figure out.
In the meantime, you could visit his website Jim Greeninger, send him a message and see if he’ll send you a written copy of his version. What’s the worst that’ll happen?
Mr. Greeninger was kind enough as to reply: