If someone turns up with a tune they've learned from dots, or from a single recorded source, it's bleedin' obvious. They will play it their way and no other way. They fail to see how vitally important it is to accommodate other people's take on the tunes.

Sometimes it is more vitally important to tell people with those alternative "takes" to get stuffed.

I learnt the Breton ballad tune "An Alarh" about 30 years ago. I first heard it sung as the tune for "The Twa Corbies", and came across it in a Breton songbook a bit later. The two agreed, because the way I first heard it sung was as Morris Blythman did it, and he got it direct from a Breton musician in the 50s.

You do not hear it done in ANYTHING like that way any more. The original is a wonderful lyrical tune with a flexible metre, which the book got down right. Some Scottish folk-rocker in the 1980s ironed that out into a rumpty-tumpty march tempo. It's boring dancefloor crap. It has lost all the individual character that made Blythman pick it out for that ballad. It is usually belted out with a thrashing DADGAD guitar accompaniment

oer his white banes when they are bare
WHOOMPA WHOOMPA WHOOMPA WHOOMP
the wind sall blaw for evermair
WOPBOPALOOPBOPABOPBAMBOOM!!!

In this instance (and a good many like it), *fuck* the folk process.