To me the only meaningful definition of a traditional musician is someone who plays traditional music, and that means music which is rooted in the traditions of a particular area. There is plenty of good music that is being written today in the traditional idiom which I think is validly called traditional music. I don't think the tune or the song itself has to be passed down through generations to become traditional, it has more to do with the style and feel of the thing which is in keeping with the tradition.

I know there are people who will have other definitions of this, but to the extent that there's any need to define this or to categorise music into boxes, this definition works for me. If someone asks me is something is traditional or not, my answer would usually be, who cares? Its much more a question of whether you like it or not.