I remember listening to Amercian Top 40 when I was stationed in Japan in the late 70s and early 80s. He really helped us stationed overseas keep up to date in American pop music...
http://www.cnn.com/2014/06/15/showbiz/casey-kasem-obit/
http://www.cnn.com/2014/06/15/showbiz/casey-kasem-obit/