Moonchild, I'm so excited to see this thread! I just bought the tape from Sandy at Falconridge folk festival, and it's been in my car tape player ever since. It's just wonderful!!
Another recording that does this for me is Graham Pirt's group, Cockersdale. I have their cd Wide Open Skies (again, thanks to Bill Sables!) and it's full of lovely harmonies.
And last night I went to hear Ruthie Foster sing in Nelson NH- the small audience filled that wonderful hall with harmonies; I don't think she's much used to that and it was a magical experience for all.