The first time I met a proper Glaswegian, I couldn't understand a single word he said. Literally - not a word. A couple of years later, I was doing a summer season in a restaurant in Fort William - the fabled McTavish's Kitchens, which some 'catters remember. One day, I met one of the KPs, who was Glaswegian, going over to the pub. He said "comin' fer a drink?" (which I understood), so in we went, got a couple of drinks and sat down. He started chatting away, with me straining my ears, but not getting much of it. After about five minutes, I was starting to get the hang of his accent, and said so. He said that his accent wasn't all that strong, and that his father had a much stronger accent. He said he had an uncle who he couldn't understand. So accents can vary even within a family.
Regarding ideas about only singing songs from ones own background or tradition, I don't come from a singing family, and grew up on rock'n'roll, skiffle and '60s pop. My only folk background was my grandad playing flute and melodeon, and my aunts' Irish dance class.
John Kelly.