In a burnt-out, four-story shopping mall on the eastern outskirts of Baghdad, Iraq, one room blared with the raucous sounds of the ‘70s and ‘80s—Metallica, Boston, Blue Oyster Cult. American troops had occupied the Sha’ab Central Market, then known as the Forward Operating Base Callahan, in 2007, and from there, American soldiers were taking in the war one day at a time—patrolling the war zone streets, training local Iraqi police, sleeping in tuna can rooms.

That day, they were playing Rock Band, Sergeant Christopher Jones said. He was there. He’d enlisted after 9/11 out in Baton Rouge, Louisiana, as a military policeman; six years later, he found himself in the desert with one PlayStation 3 and a platoon full of Rock Band fanatics.