I had come across common ballad themes running across Europe, for example a Czech ballad that follows the story of the Two Magicians.

I would like to research how much folksolg is Bohemian in origin, and how much crossover their has been through Roma communities bu tthat I think should be another thread.

The term pure and unadulterated is totally meaningless in respect of folksong as the 'folk process' is a process of adulteration as songs migrate from community to community, and at the point of collection we don't know how much adulteration has already taken place.