Jim Bainbridge -
I couldn't copyright my 'arrangements' because like most singers/musicians with a base in traditional material, every time I play a tune or sing a song, it's a slightly different version!

This puts Jim in the same class as a lot of traditional performers. Let's just consider a few that I know (or knew) well:-
* Jim's greatest hero (and mine) was Davie Stewart. I was fortunate to hear him many times during his latter years. His melodeon accompaniments are endlessly inventive and he made his own musical rules for them. He sounds a lot of the time like a piper who has taken up the squeezebox (which he was!) The words of the songs were never settled and he could invent verses as he performed to suit the situation. On his Topic album he ends off one of his songs with a few lines suggesting that it would be a good time to stop recording and have a cup of tea.
* You could never expect Gordon Hall to sing a song in the same way twice. If his songs were not long enough to start with, he found ways of segueing seamlessly from one song into another. I can remember him singing The Sussex Molecatcher and some time later he had blended it into The Drowned Lover and I remember thinking "When did that happen?" He would sometimes sing a song straight and then go into his parody of it.
* I have many recordings and printed versions of songs sung by Willie Scott including quite a number that I made myself. Willie's changes of phrasing and use of words were quite slight. It felt to me that he was unlessly trying, consciously or unconsciously to polish his songs into the perfect version.
* In the last 50-odd years, I have heard four generations of The Copper Family singing - five if I include the recordings of Jim & John - and the famed home-made harmonies of their singing change from generation to generation.