About the last song, sounds like a Serbian-Bulgarian mix to me. I presume it’s the modern Macedonian language (not the dialect)?

And, yeah, the Rhodopean dialects are the most undecipherable, probably because they’re also the most archaic. Heck, I think they even still use the nosovkas. Still, it’s easier to understand in songs (especially if you also have the lyrics), but I also remember how much we laughed at some of the words (especially at “glyodam”) of this song when we studied it in 5th grade: