Recently, I've been listening to Techno music. It is different and new for me. But some of it, the stuff I enjoy makes me sleepy. My friend sent me a link and by the end of it I was almost asleep. How does the frequencies of the music played effect the listener. And what frequencies lull one into sleep? And what combination of body frequencies and produced frequencies cause drowsiness? Just like a certain frequencies are ear splitting and cause painful headaches. Are there any know frequencies that make one happy, sad, sleepy or other emotions?