If you’ve ever flipped through the radio dial — not satellite, not podcasts, but good old-fashioned AM and FM radio — you may have noticed something. Right wing radio talk is everywhere.But the airwaves weren't always so dominated by such a narrow range of voices. Reporter and friend of the show Katie Thornton has the story of how talk radio has evolved (and perhaps devolved at times) over the past century, and what all of it means for the airwaves today.The Divided DialHear the rest of the the series from On the Media