"uestion of authorship doesn't come into it. Any song can become 'traditional' if it is sung by a particular type of community over a long enough period."

Yes it does! And that's exact;y why we need to separate the two meanings of the word traditional - apart from the legal one which means 'in public ownership.'

The Tradition is mostly agreed to mean that now-closed body of works, "of unknown authorship, which have survived generations of oral transmission." It's NOT possible to add to this part of the catalogue, because the very special methods by which it was formed have now passed into history. There is too much rapid cross-contamination today by recorded media and other means for any new songs to acquire that unique geographical separation and re-formation which makes this body of work so particularly interesting from an folklore and musical/archeological point of view. This needs to be recognised - far too many people still don;t understand. This material be good bad or indifferent - you can judge it how you like from a musical point of view - and you can do what you like with it too, but it method of creation MUST be recognised and respected - and tags attached, so people can continue to derive information from this musical element of hsitory. That's why some labels DO matter. Think Time Team.

Meanwhile we ALSO need a new or different word to describe newer songs that have become or are maybe becoming traditional (small t) by modern means (such as being "sung by a particular type of community over a long enough period"), but where the author IS known.

This is for two reasons: Firstly because until 70 years after that author's death the work is copyright and royalties are due. To call a copyrighted work tradtional is no less than theft. And secondly because even once the work has passed out of copyright and is legally in public ownership, that writer sill deserves credit for his or her work. To call a publicly-owned work of known authorship traditional is lazy, rude and ungrateful.