"Officially-sanctioned music that has to toe the official line."

I think that's limited to national anthems, religious hymns, and music in North Korea.

As I and others have said for years, "folk music" is a sometimes useful but extremely vague label. Except for scholarly use, I think the opinions of a robot in this case are as valid as anybody's.

Especially with the encouragement of music-industry marketing strategy in the sixties, people apply it to all sorts of things that academics do not. I find that annoying but gave up caring fifty years ago.

But I do believe this is the first time I've seen folk song defined mainly by *subject matter* rather than by origin, transmission, milieu, style, or all three.