"The practice is old, it occurs with some folk songs."
As far as British and Irish singing It is an 'old' revival affectation; the older generation of singers seldom, if ever did it; many frowned on it when it became fashionable.
Our songs are mainly narrative and it has always seemed pointless to me to reach the climax of a story and start talking about clocks striking thirteen all over again.
Speaking the last line (usually the last few words) is mainly an Irish practice - when we saw it happen with the older singers it was invariably in rooms full of strangers - a sort of self-assurance that these 'incomers' had understood what they had just been told.
Again, many of the old boys disapproved of it - we were specifically told that it ever happened in the farmhouse kitchens where the singing took place.
Quite often then, the listeners would join in with the last few words of a song - a sort of affirmation of its familiarity among people to whom the songs were part of their lives.
I've just re-listened to about four hundred songs we recorded from Clare singers and cannot recall the practice with any of the 'big' traditional singers here, though I will admit, I hear it sometimes from the present generation, but then again, not that often.
Pausing before last few words - nope - exclusive to younger singers
Jim Carroll