I don't think they've passed legislation on the subject yet. A degree of personal freedom of choice is still alowed to the performer.

i remember Burl Ives saying about his rendition of Barbara ellen that in his nind he while he was singing he always went through the same cottage door, across the kitchen, up the same stairs, the same bedroom where the same young man lay dying on the same bed.

But that was his approach. I remember talking to one very experienced performer who suddenly added an almost reggae beat to a trad ballad, quite unexpectedly. I asked him about it afterwards, he said - I just felt the audience needed lifting a bit, but that was the song I wanted to sing......