"the leadership of a few traditional music lovers who made a concerted effort to do this.....but somehow they attracted many followers."

Even in vibrant traditional music cultures that never had 'folk revivals' initiated by outsiders, this seems to be the case. I don't think Cajun music would be in the rude health it seems to be, without the passionate advocacy of Dewey Balfa (himself from within the tradition, of course), Michael Doucet and others. the same is true in my experience of Quebecois music.

"DIY music making continues to be a key aspect of British culture"

I'm sure that it is, although I'd guess that it's far from universal (the only vaguely relevant figures I could find on the web reckoned that 6% of the US population owns a guitar, although that might be an underestimate). And Rob Naylor is right in saying that instruments and technology are priced within the grasp of many more people these days than formerly.

I tend to agree with Steve Gardham, when he said "we would be best treating what happens today as separate traditions from those that happened a century and more ago", which is not, of course, to say that what happens now is inferior. Also with Martin Ryan, that as far as modern songs 'becoming traditional' is concerned, it's simply too early to say. I still await the evidence that recent songs are getting passed on down the generations in the way that allowed Sheila Kay Adams to learn 'The Outlandish Knight' from her mother in North Carolina, and still be singing in 2011 a ballad known in Britain the best of 250 years previously (and much older than that in Europe), which Cecil Sharp himself noted down from Sheila Kay's great-great-Aunt Mary Sands in 1916.

Sheila Kay talks about her family and sings 'The Outlandish Knight'