Obviously whether "folk" music is in decline depends on how you define "folk" music. If we define it broadly as simply all music made by human beings, we are zoologically correct--human music differs from the music (if we call it that) of whales and birds--and we will find no evidence of decline. But then we will need to find other words in order to classify and describe historical and other distinctions within the field of human music.

On the other hand we might define "folk music" so narrowly we will be forced to conclude that it never existed.

One definition which I greatly dislike defines "folk" music as meeting what I call (1) the criterion of non-literacy and (2) the criterion of ignorance. According to this definition, "folk" music is music which is transmitted without the aid of writing or recording or electromagnetic broadcast among peoply who do not distinguish it from other kinds of music.

I dislike this definition especially for the second part, what I call the criterion of ignorance. I doubt that it describes the realities that exist among the very people whom I suspect the formulators of the criterion had in mind when they formulated it. I think it may rather verge on being an insult. The first criterion does sometimes apply, but I suspect that it can't be applied too strictly to the pragmatic realities workaday life in literate societies. Also, as George Pullen Jackson pointed out, the criterion of non-literacy was partly responsible for the folklorists overlooking the shape-note singing societies for a number of years.

The venerable definition of "continuity, variation, and selection" avoids patronizing anyone and provides a useful description of how music evolves. But much music which the folklorists would not consider "folk" music evolves by means of these same processes. J. S. Bach selected and varied old German hymns and passed them on to subsequent generations (continuity), which have arranged them (variation) for instruments, ensembles, and media which did not even exist in J. S. Bach's day.

So in my posting of April 24 I tried to avoid the "folk" definition trap altogether. Instead I tried to define the category of (1) one-line (2) nearly diatonic melody of (3) consistent tonality throughout. This describes much of what folklorists would call "folk" music and leaves plenty of room to trace the historical development of the various cultural settings in which it is used. One may be able to identify many "declines" of various uses to which this category of music is put (player pianos? maybe they are flourishing, maybe they are declining).