Are you sure they were Polish. there is a large and culturally active community in Manchester. However EFDSS were fond of featuring the Orlick Ukranian Dancers from Manchester.

I suspect the group on the EFDSS cover were the Bangra Punjab, located in Birmingham I think.

Regarding ethnic musiscians in Yorkshire, I suspect the Indian communities there as elsewhere have quite a large number of classical musicians. There are far more musicians in India than jobs, so a lot of them work in the professions, eg law or medicine, and play music on the side.

More to the point, some years ago a west African kora player from Leeds was featured in a concert at the Philharmonic in Liverpool. I regret to say I can't remember the guy's name, or the name of the Indian musician who brought him over. However, both were at the Music department of Leeds university, so that may well be a good place to start asking.

Also, the department of music at Sheffield university offers an MA in ehnomusicology, so someone there may be able to offer a few leads.

I feel quite ashamed typing this. There are ethnic communities from all over the world here in Britain. Music for them is a lifeline to the world they left behind and I am fascinated by the sounds they produce. Perhaps, instead of bemoaning the death of our own traditions, we should be celebrating theirs.