The "Heaven's Cove was a wondrous sight" section reminds me musically of something else but I can't think what it is.
The vocal lines remind me of a scene in
Mockingjay part 1, where Katniss is singing a song called "The Hanging Tree". I'm not exactly sure how to describe that sort of music, but to me it sounds sort of religious, and irish, so I'd go with that.
I'd gladly post a clip of that scene, but I'm not sure if it's permitted?
However, Heaven's Cove doesn't so much tell the events in the story but merely sets the scene for future events to play out.
That's one of the reasons why I think it could fit in future setlist (also, it doesn't mention any characters).