Generally speaking "folk" in this context tends to mean a couple of guitars. With us, the hymns we use might be whatever comes up. Actually the only one's I'd count as part of a folk tradition tend to be the old ones mostly from the 19th century, where you see people put down the hymn books and sing the words they already know.
Gradually more of the newer ones get accepted and become part of the tradition.

I wish we were up to doing O'Riada.