"The finest and most prolific writer on songs based on traditional forms always referred to what he sang as "folk songs and new songs that derive their inspiration from the older ones" – good enough for Ewan MacColl, certainly good enough for me. "

Hard to argue with that, Jim, but it doesn't exactly trip off the tongue. Most people want something a bit snappier, and 'folk' is the word they have chosen to use.

"new songs using folk forms, these have always been part of any evening in folk clubs I have frequented throughout my life"

Unless you have been extraordinarily selective in the clubs you frequented, I find it hard to believe they would not also have included new songs with little if any connection with folk forms.

" – why on earth should you want to call them anything other than new songs?"

"New songs" may be sufficient in a very specific context, but does nothing to place them in any particular genre. "New songs" could be pop, jazz, classical, anything. There is a need for a word to describe songs which don't fit into other categories and which can sit reasonably comfortably along side folk songs and songs using folk forms. Once again, the word in common usage for this is 'folk'.