These are Gordian knots you-all are trying to untie! I'll just tack on a tiny example of how songs change: Mom and I were singing a little thing she liked when she was being courted by her future husband, my Dad. She sang it around the house until HER Mom declared she was goin to "stop her mouth with a dishrag!" Mom laughed and then we sang together the first verse:

Somebody's tall and handsome
Somebody's fond and true;
Somebody's hair is very dark-
Somebody's eyes are too.

"Hey wait a minute- that's supposed to be, 'eyes are blue'", I hollered.
Mom's little smile, then, " Well 'twas- I changed it!"