If you put several thousand of the world's best athletes in a stadium and make them all listen to Adele, do they all cry simultaneously?
London 2012's organizers had a shrewd way of finding out: booking her for the Closing Ceremony. They will then be cheered up by the Spice Girls, and the Who and many other acts will perform as well. The closing event of the Olympics is basically a concert, as opposed to the opening one, which is a combo historical reenactment/parade, and it will take place Sunday night as a successful summer games comes to a close with America on top of the medal table. The ceremony will presumably feature a hand off of hosting duties to Rio de Janeiro, who will host the 2016 games.
The ceremonies will begin via tape delay at 8:30 p.m. on NBC, but unlike the Opening Ceremony, will also be live-streamd starting at 4 p.m. on NBC's official Olympics website, if you can't wait to see it live.