Mostly to meet people they hadn't seen for a long time, and for enjoyment. They'd all congregate in the pub and have a dance and a song, meet people they hadn't seen in a long time, because people didn't travel as far, back then, as they do now. They'd go away, perhaps they wouldn't see them for months. At a particular time of the year. There used to be what they call jobbers, used to travel from county to county, they'd get a week's work on one farm or another, anywhere they could get a bed in the barn and a bit of food - they had a bit of news to carry and perhaps a song that they'd picked up.
Several travellers stay in one place, they'd have a song or two.
They'd meet at weddings and have a bit of a do there, a celebration. Yes, I think that's where some of the mispronunciation came in, they'd pick it up the best they could, in a short time. They couldn't read or write, they were illiterate, it had to be passed from one to the other. You see, when I came along I was years behind the others. My brothers and sisters was years older than me.