Mayer's fourth studio CD debuted atop the Billboard charts upon its 2009 release. Here are note-for-note transcriptions of the singles "Who Says," "Heartbreak Warfare" and nine more: All We Ever Do Is Say Goodbye * Assassin * Cross Road Blues (Crossroads) * Do You Know Me * Edge of Desire * Friends, Lovers or Nothing * Half of My Heart * Perfectly Lonely * War of My Life.