I would say that Puccini would have a legitimate right to scream like hell if someone were to rewrite portions of La Boheme. Same with Cole Porter, Irving Berlin, Bruce Springsteen, or anyone else for that matter—with the option of taking legal action.

BUT:— Without getting into the "what is a folk song" can of worms, some singer/songwriters insist that the songs they write are "folk songs." In my opinion, when they do that, they're just begging for anyone who wants to come along and folk process their stuff. What recourse does the writer of "folk songs" have when singers modifying folk songs to their own taste is traditional? I wonder what the legal opinion would be then.

Don Firth