I think it was a first for Desert Island Discs, to have someone record a song especially for the programme. An odd thing to do when you think that the whole idea of the show is to play your (presumably) already recorded favourite discs. I did wonder if Christy did it to show that songs have lives outside the singer and can be sung by anyone, so long as they have a talent for singing? If that was the case, that was a true folk attitude in the tradition; but I am only speculating here. It was, as expected, a wonderful show.