I've no idea because I can't hear the difference.

Well, maybe this is the problem. Many of us hear strong differences between traditional music and contemporary music. This is why we would like them to be separate genres. This doesn't have anything to do with whether or not the song is any good. It doesn't have anything to do with whether or not people should sing it, or where they should sing it. It just means it's a different genre of music.

Before I read this thread, I had never heard of the 1954 definition, and yet I've been playing traditional music -- and defining it the same way as the 1954 definition -- for most of my adult life. In saying this, I'm not trying to tell anyone else what to play, or making any judgments about what's good and not good. I'm simply saying that there are two quite different genres of music encompassed by the "folk" label, and they are mutually exclusive.

The 1954 theory is somewhat like the theory of evolution. No one would say it covers every possible scenario, or that it supplies the whole answer for anything. It is, however, a theory that describes and accounts for a set of observed phenomena. It tells us how and why the music sounds like it does, has the variants it has, and has spread the way it has.

I don't know why anyone thinks that those of us who are arguing in favor of the 1954 definition are trying to put music on a shelf, draw rings around anything, or tell anyone what they should or shouldn't play. Most everyone has been at some pains to say quite the opposite. No policing! Just a discussion of the definition of a word. Traditional music is certainly not on a shelf for me. It's a living, breathing thing and can be handled in almost any way that anyone likes. It is as much a folk song when done by a rock band as it is when sung unaccompanied -- something that can't be said about most singer/songwriter music. I've often thought that giving a singer/songwriter a big recording budget tends to change the music from "folk" to either pop msic or country music.

Traditional music is just not the same as contemporary song, and no amount of saying "it's all folk" is going to make many of us start using the word "folk" to describe anything that gets done in a "folky" context.