The Pont y Gogledd tune in the John Thomas MS notebook is precisely why I started this thread. i have for long being tinkering around with the using clusters of place-names in tune MS books for identifying where the musicians who noted the tunes were from (they often omitted to put sufficient information in their books, very inconsderately). Cass Meurig identifies this book on the basis of the dialect of Welsh used as coming from NE Wales.
   On the basis of tune name clusters I would hazard a guess at the Welshpool(Trallwng) area, but with no great probability of being within better than 20 miles. But I am intrigued by the Pont y Gogledd tune name. Is there a Pont y Gogledd in Wales(or several Pont y Gogledds??), or is Pont y Gogledd an 18th century name for Bridgenorth?
   John Thomas has plenty of north wales place-names, also Shropshire,Cheshire,Lancashire and Yorkshire...as well as much further afield as you would expect(Ireland, scotland, London etc). But we can often learn a lot about the music from the more obscure locally named tunes not known widely elsewhere. Anyway, one name wont affect the picture very much (that's the joy of clusters and statistics).North wales, very near the Shropshire border is my bet, for John Thomas. but for Pont y Gogledd, who knows.