Sound was used in ancient history to control populations! Since the government regulated what music could be heard, they controlled what vibratory frequencies interacted with people, affecting their minds, bodies and thoughts. I know this sounds screwy, but the ancient Chinese did this for thousands of years and their governments (dynasties) lasted for a very long time. I don't know about you, but four years of one president is usually enough for me! However, our government doesn't control the music and sounds that we listen to!