This is the main theme for a video game, Civ IV ... as is obvious from the title. Another Peter Hollens song. And, really, this guy is amazing. I'd ask how this guy is not considered a professional, but looking at his recording equipment, he looks like one to me.
Anyway, it's really music to write to -- and no, you can't sing along to it. :)
However, don't worry people, this will not be just a music post. There is, of all things, a short story. Yes, a short story. It's been a while since I did one of those. If you remember Scott Murphy from The Pius Trilogy, you might remember that he's just a spy. He's, at most, an infiltrator. He doesn't do fights. He doesn't punch people. He doesn't do shootouts. He doesn't believe in violence -- because he's a spy, if he has to fight, he's not doing his job.
In this case, a fight comes to him. And Scott, a pale, anemic fellow, who has to fight a legion of terrorists with absolutely no preparation or warning.