Hearing Elvis Presley, Bob Dylan once said, was "like busting out of jail." But what happens when popular music isn't as simple as rock-and-roll rebellion? How does pop respond to such events as a decade-long war in Iraq and Hurricane Katrina? In Pop When the World Falls Apart, a diverse array of music writers, scholars, and enthusiasts reflect on popular music's role-as commentary, as refuge, and as rallying cry-in times of military conflict,...