"I don't make culture, I sell it" Dick Clark once remarked. Indeed, the man who reigned as host of American Bandstand for nearly four decades may not have invented rock 'n' roll, but he sold it to the American public better than anyone before or since. Before Clark, rock 'n' roll was the step child of radio--which took to playing records as a cost-saving measure after television siphoned off radios most lucrative sponsors. But it was network television--and...