Tonight the Top 4 finalists will perform live for the nation, vying for the American Idol crown. The contestants sing their hearts out in hopes of winning America's vote and surviving another week in the competition. Tune in to see who impresses the judges and who buckles under the pressure. Tonight's theme: Rock and Roll Hall of Fame. Performing tonight: David Archuleta, Jason Castro, David Cook, and Syesha Mercado.