If you want to know a bit more about English "glee" singing, check out the Musical Traditions article on the the Millen family, a family from Kent that was only recently "discovered." (There's a new cd available). (I've only recently read it; sorry, I don't feel qualified to digest the content for you, yet...)

Regarding the Coppers' style, Peter Kennedy said, "Although much of the harmony might at first sound similar to church choir or glee club, there is much in the style which could be an example of primitive folk polyphony survival. Their practice is to give a 'hovering effect' in passage from one main note to another, the main notes themselves very often being in unison. Their style is not confined to their own family as I have heard other family pairs, not only in the region of the South Downs, but also in the Thames Valley area." (In the notes for the Folk-Legacy album, "English Shepherd and Farming Songs" sung by Bob and Ron Copper, recently re-issued/reformatted? and released by Topic.)

And to amend Peg's note above from 2/12, Tony Barrand's partner is John Roberts.

~ Becky in Tucson