This was an experimental broadcast to see if Quadraphonic Sound (using Dolby Pro-Logic II) could encoded, transmitted, received and successfully decoded back into quadraphonic sound, using AM broadcasting. This video contains the over-the-air recording of Stereo 1630 KCJJ in Coralville, IA - during the Robb Spewak show - captured using the Meduci PRO1k AM stereo tuner. This also shows how good AM stereo can sound! To play this properly, hook you computer up to a Dolby Pro-Logic receiver and decode it using the "music mode."
I think this proves that it is possible to get surround sound using an AM radio signal.