If a song evolves is totally out of the hands of the music industry and the creator.

One of my songs was adapted and given naughty words by the fans of Bayern Munich football club and sung on the terraces (if those cultured EU countries have terraces). I didn't know anything about it. I doubt if I got any royalties.

I seem to remember Lloyd Webber's Jesu Christ Superstar suffered a similar fate:-
Ryan Giggs! Superstar!
How many goals have you scored so far

The song Son of my Father was adopted by Aston Villa fans in the 1970's

Oh Jolly Roger!
Roger! Roger! Roger!
Roger Hinds!.

One publisher who owned three of my songs and had some success with them,   went bankrupt. this was considered good business practice in the 1980's. the songs passed to the files of a huge conglomerate who do bugger all with them. I believe the the guy lives in Hawaii.

Its made me very wary of publishers.