Summer Jams, the '09 Edition

Forget baseball, politics, apple pie or a vague disdain for the corporate aristocracy, the element that binds American society together in an increasingly atomized post-millennial milieu is the Summer Jam. Think Jay-Z, Rihanna, Outkast or Beyonce. Think the moon landing, except with more sex, better hooks and less Nixon. It's the alpha and omega of pop music -- bigger than big and blasting out of ever car stereo, club speaker, poolside radio and computer headphone. Who’s going to put the bump in your trunk this year? Here are our picks for the contenders.