well johnny - i'd say sod the politicians and politics. lets think in terms of great Britain as was before 1922.

I think a lot of the regional differences are a bit arbitrary. most of us are mixed race, and the cities are full of Irish and Welsh people and there is a great cross fertilisation of songs.

does a Belfast person who comes to work in Sheffield still sing The Doffin Mistress - yeh course they do. they acquire a Sheffield accent and put Yorkshire words and mill slang in over time. I mean that's just human behaviour.

similarly off to Dublin in the green - many regional variations can be heard in English folk clubs.