I have managed to persuade Iraqis and Afghans to come and sing at a pub session in Stoke...it doesnt have to be a problem the pub thing. Also many Africans. You do have to be actively welcoming though. I dont think many of the folk clubs in this area are showing any interest, for example. The Sandbach folk club was extremely welcoming, and had its biggest turnout for ages for some African guests, but alas this is not being repeated elsewhere as much as I would like to see.