As Katniss, Gale and the revolution's propaganda team head back to District 12, Katniss is encouraged to sing for the group (and for the cameras, of course), resulting in either the most uplifting or the cheesiest scene in the series depending on your own mindset. Katniss sings "The Hanging Tree", the lyrics of which were originally written by author Collins for the Mockingjay novel, as an anti-Capitol anthem, with Plutarch noting that he changed one lyric from "necklace of rope" to "necklace of hope" to give it a more positive message. The song had sold over a million copies by January of this year, so while it seems a little jarringly-placed in the movie, it's undeniably popular.