Providing the hook for Eminem's murder ballad "Stan" is an odd way for a gentle English singer to launch a career. But Dido's featherweight soul has always harbored a dark side, and her third set expands her wine-bar sound with shadows. Co-producer Jon Brion adds cinematic breadth to songs about emotional crossroads: The strings-laden "Never Want to Say It's Love" finds the singer gulping pills,...