"After all, who wrote the song is a lot less important than who chose keep on singing it and to pass it on to the next generation."
This is something that can't be repeated enough.
"I was not aware "anonymous" was a criteria for songs or tunes getting into oral traditions"
That is true Jon; there are exceptions, particularly in Ireland, but it's worth remembering that Carolan's music does not seem to have been played continuously since it was composed (not by the folk anyway) but owes its present popularity to Donal O'Sullivan's 'Carolan; The Life, Times and Music of an Irish Harper' (published 1958).
I spent about a year in Manchester Central Library poring over microfilm copies of the 19th century 'Reform' newspapers which included columns of political songs; forget the titles, but seem to remember 'Black Dwarf' was among them. It's interesting to compare the somewhat turgid style of composition with the traditional songs of the period.
The same goes for the small collection of miners songs in Liverpool's Picton Library.
We were lucky while working with Irish Travellers to have witnessed a living tradition (for a short period anyway - until they all got portable televisions). There, new songs were being made regularly and sucked into the community. One of the common features of these was that despite the fact that some of them had been made within a few years of our recording them, nobody could remember who made them. Anonymity seemed to be a common feature and authorship did not seem important.
Jim Carroll