The definition of "traditional" we used to use to avoid fisticuffs was that the song had to have undergone oral transmission and become changed in the process; so "We all live in a yellow submarine" is not trad, but the football chant "We all live at the Hilary Street end" is. "Anon" simply means we don;t know who wrote it, which is a subtly but significant difference.

Just to complicate matters, we know that, for example, Robert Burns collected trad songs and "cleaned them up" for publication under his own name. I suppose that "improvement" by Anon makes something trad...?

BTW, what I wondered way back at the start of this thread was: what's the average (mode, not mean!) of songs we think of as traditional "old" songs when we sing them in public?

Steve