Gymanfa Ganu (Cymanfa Ganu) in Oregon
Heard from a friend that Bryn Seion Welsh Church in Oregon is preparing for a-
Gymanfa Ganu, a magnificent Welsh singing festival with people coming for miles to sing hymns in four-part harmony.
"The hymns, in turn, became the folk songs of the country, and singing hymns became part of everyday life in such places as mines, pubs and rugby games."
There is also a North American Gymanfa Ganu Festival. And many festivals in Wales.
Wish I could find a video example. Love Divine sung in Welsh to the melody Blaenwern is the closest I came.