Let's continue on with medieval Christianity, shall we? (Seeing as my last post was on Hildegarde.)
"Brother Sun Sister Moon" isn't really a postmodern hymn, because it was written by Saint Francis back in the day. What makes it postmodern is Donovan's singing of it, and the layer of 60s earthiness that Zeffirelli added to the film. I think this is appropriation and reinterpretation at its best.
This song comes from the movie of the same name, and Brother Sun Sister Moon is one of my favorite movies ever. You must watch it if you haven't already!