All the good strong chorus clubs go for harmonies. At the Durham Club back in the day we revelled in pushing the envelope as far as we could. And some of uis still do! Most folk clubs we go to now do likewise - in fact in night 40 years o' folkin' I've never heard unison chorus singing, especially on Tyneside...

I suspect the Copper Family weren't unique; their influence went on the inspire other acapella harmony groups from the Young Tradition to the Watersons to the Wilsons to the various groups singing today in fine old style, be they Fisherman's Friends style chantey groups or the Young Uns. Then you've got that whole shape note thing Phil & Cath are involved with, which has echoes of the sort of thing you might hear around the pubs of Sheffield in the coming weeks. The Yorkshire Carolling tradition is an old one - and it extends beyond Yorkshire too - I knew old Durham miners who would play their harmonies from farm to farm on one string fiddles made from cigar boxes.