^ I guess you could say that, but really it's just a badass song that the Lannisters ensure everyone knows the words to so as to communicate the all important message that they are not to be fucked with. EDIT: in retrospect I wonder why they did that? It's not like they've made a point of explaining in the show what that song is all about and the backstory with house Reyne etc. The only people who are going to be all about it are the book-readers. Either it's a pretty significant nod to said readers (The National is a reasonably big deal) or the band was just really into doing it.