Certainly, none of the seven different Manchester Hornpipes can be definitely proved to have been written in Manchester. These things by the nature are not very well documented. They could possibly all have been written in Japan. But all i am suggesteing is that if you add together vast numbers of references to fiddlers in Lancashire over a long period of time, bagipers etc as well, and vast numbers of tunes with Lancashire placenames in the title with a provenance extending over the 16/17/18/19 centuries: well, the most logical explanation is that there was a fair amount of that kind of dance music around. Of course all these references could have been forged in some strange kind of Dan VBrown conspiracy, and all the tunes actually composed this year in Tokyo. But frankly, I would go for the obvious explanation. Which is that the north of England was cram full of traditional folk music at this period.