Maybe it depends how well you play it…
If you play it poorly, no one will know the song and no harm, no blood…
But if you play it really well, then someone is liable to want to sue your ass for something, somewhere, just to make a buck! This seems to be the type of world we live in.
Actually, this is a great question @AstridHandbikebee63. I too see covers on YouTube and many are very good. Not sure how the rights work.
It would be fun for some of us on this forum to post songs to share with each other. The other day when I was watching different versions of “When the Saints Come Marching In”, suggested by @Luke, it occurred to me we could do something similar, where we each upload our version of a particular song.
I see it more as a learning experience than anything else. Something where we can share with each other.
For published works, there is a 50 year time frame, after which they go into Public Domain and anyone can use them.
Is there anything similar for music? 
Maybe we could all do our best rendition of…
Itsy Bitsy Spider or some other such song?
I don’t think anyone can claim rights to them, but I may be mistaken … 