You've hit it Mark - how does a song become traditional unless someone first writes it and sings it round?

There are still some folk out there who are adamantly arguing that certain songs (mostly from the Sy Khan stable) are traditional and are thoroughly chastened when they learn that the author is still alive - it's like Les Barker says: 'Here's a traditional song that I've written'.

The crux of the question has to be (and I say this with due trepidation and knowledge that there must be at least 49 threads already on this, which some clever dick will attach in that neat way that they do), when does a song become a traditional song? How old or how popular does it have to be? Some would say that 'She moved through the fair' is trad. but it's fairly recent, 'My Laggan Love' and 'Fiddler's Green' are also younger than they seem....

(Incidentally, it's also amusing that when I posted this, the adverts below were for, respectively 'Endangered Species' and 'Brain Tumour patients'.... does this mean that Trad is endangered and songwriters need their heads examined?)

LTS