Here's a pretty interesting radio spot from DDB Chicago for the Field Museum's Genghis Khan exhibit. To illustrate the two very different sides of the Mongol leader, the agency used the stereo sound to give the spot two different tracks—you can turn the balance on your stereo to the left to hear about "Khan the barbarian," or to the right to hear about "Khan the innovator." Click below to hear the ad—it works well with headphones. (Just don't go messing about with your car radio while you're driving. That's barbaric.) The copy is also pretty humorous, particularly the descriptions of Khan the innovator. Nice work on a seemingly dry piece of business.