Ok. Not enough people hate me yet, so let me have another go. My previous contribution was made on the assumption that 'from the singing of' was confined to acknowledgments of traditional source singers. Clearly some people do not regard this as taken as read.

I do not generally acknowledge material as being from revival singers on record unless:
1) they wrote it or substantially rewrote it
2) I think they worked inordinately hard to find it
3) there is a particular reason for such an acknowledgment to be relevant to the performance (e.g. the singer has just died, or five other people have just done songs recorded by the same person).

My reasons for for this are:
1) I do not ever acknowledge that I have made a deliberate attempt to sing any song in the style of a particular revival singer (though others are entitled to think that I do). I do make this acknowledgment in the case of source singers (though others are entitled to think that I fail lamentably).
2) As a general rule (and there may be a few exceptions to both ends of this statement) revivalist singers record songs to make money and source singers didn't. I reiterate what I said in my first posting - I regard 'from the singing of' as being a thank you and a tiny medal for the people who for no gain to themselves gave me a piece of tradition that would otherwise have been lost.

I now sit back to be attacked for my disrespect, if not my hatred, for revivalist singers. That is not my attitude. I am after all one myself. I merely state why I think the conditions for saying 'I got this from the singing of' are different in the two cases. And why I am sufficiently 'affected' to want to say it at all.