After installing iOS 7 on my iphone 4 I saw radio in the music app and shortly after it disappeared. Very frustrating. Spent hours trying to bring it back. Had option to "create station" from a song or artist but would get a notification that a station couldn't be made. Finally I thought to "delete" the music app (knowing that as a standard iOS app it can't be, but I have it in my dock so that at least is a possible problem??). So I made the icon all shaky for a sec, returned to normal, leaving it in the dock just for fun, opened it again and THE WHOLE APP GOT ALL SHAKY! A second later everything was normal and radio was back. Not sure if this'll help your problem, but can't hurt to try.