That's a great article. One great point it brings up is how much music can affect your mood. If you play sad and depressing music, it tends to make you sad and depressed! If you play loud, angry music, it encourages you to be loud and angry. So it's sort of a never-ending cycle. If you want to be happy and calm, it makes sense to play happy, calming music.
It always amazes me to learn just how much of our world is self-created. Two people can be in the exact same situation, and one person can be sad and annoyed, while the other can be content and happy. It all depends on how you view things.