well I dont care about differences,but all music whether its english or celtic should have one similiarity.It should be music, it should be able to convey emotions, and the performers should have respect for and like their material. Musicians and singers should not worship technical virtuosity for its own sake, but remember the old blues singers, who sang about how they felt, when they sang the blues. its a mistake to get lost on a trail of pan celtic or pan anglo saxon national identity .if asong is a good song it doesnt matter where it comes from America England Ireland or Timbuctoo.