I would suspect that there are a great number of places known as Pont y Gogledd. Now - this is purely speculation, but it's the sort of reference which I would expect to find liberally applied at a very local level. So, within what would have been the 18th/19th century equivalent of "Travel To Work" area, Pont y Gogledd would have been the bridge at the north end of an estate, or town, or parish. (Is there a North Bridge within the old areas of Shrewsbury or Chester, I wonder?) There are, for instance, a few places known as Pontrickets which, oddly enough, is actually 'Pont Rhyd y Gad' or 'the bridge at the ford of the battle'.   

I think John Thomas is, generally, 'placed' around the Borders/mid Wales area so it would be worthwhile looking at some old maps. My family are from a bit north of there, but I can't think of anywhere known as Pont y Gogledd. And as Cass also points out, I think, sometimes the Welsh fiddlers simply translated tune names ... so it could be a geographical reference to somewhere in England or Scotland, I suppose.

Good to hear that you've got the book, greg. Any further comments?

siân