guessed wrote
I am not quite comfortable with the use of 'ours' by collectors to refer to songs that they have 'collected'.

Major embarrassing moment!
Tina and I were singing in a concert at the Newton Abbott folk festival some time in the mid 1970s and as part of our set we sang Billy Taylor learned directly from Cameron & Jane Turriff who sang it together in unison which was what we do.
Peter Kennedy had a stall in the hall and was selling a selection of his Folktrax cassettes - (yes, I know all about their provenance). At the end of the concert as I walked past his stall, he attracted my attention to speak to me:-
> Who did you learn that version of Billy Taylor from?
> We learned it from Cameron & Jane Turriff when we were staying with them in Fetterangus.
> Oh! That's all right then.... that's not one of mine!

I can lose my temper but only do so rarely and generally there is a slow and gradual build up. On this occasion I went from 0% to 100% in one second. I bawled at him at the top of my voice -
>What f***ing difference would it have made if it had been one of yours?
Peter ran out of the hall. The people going out of the concert fell silent and all eyes turned on me.
I was mortified.