When you're really bummed out, the last thing you want to hear is up-tempo and positive. And it lets you know that you're not alone, that somebody has hurt before. It works the same way with chick songs as it does with political songs. When you hear somebody singing about these things, you know that you're not alone, that somebody else is suspicious of what's going on around us in the world. So you don't feel like you're crazy, and you feel like you might be able to make a difference.