John Mayer Battle Stidies Gutar Tab. Mayer's fourth studio CD debuted top 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; Crossroads Do You Know Me; Edge of Desire; Friends, Lovers or Nothing; Half of My Heart; Perfectly Lonely; War of My Life.