Hamish: I've heard Bill Jones do William Taylor, solo voice accompanying herself on keyboard. I don't think it can be identical note-for-note with Altan, who are not (I understand) a solo female with keyboard. But then I'm not a musician, what do I know?

I do know that my wife and daughter sing in folk clubs, and they sing songs they've learnt from CDs. They vary them a bit to suit their own voices, but they still recognisable as so-and-so's versions. (Well, often, anyway.) They usually say something about the song and its origins, but not always. I thought that this was just the way things were done, and part of the folk tradition, etc.

Meg adds that she is sometimes surprised, going back to the CD, how different "her version" is from the source track. For example, decoration can replace harmony.