John Mayer's Battle Studies comes three years after his critically acclaimed 2006 album, Continuum. Incorporating the warmth, melodies and simplicity of 70's and 80's California rock/pop, Battle Studies is a confessional, relaxed and liberated album recorded in a private home in California where Mayer lived and worked over the course of six months before wrapping at the famed Capitol Studios in Los Angeles. The album's first single, "Who Says" challenges conventional standards of what one can accomplish or undertake - despite society's constraints. Battle Studies also showcases universal themes on "Heartbreak Warfare," "Assassin," and "War of My Life," while flexing guitar chops on "Rock Song," and a reinterpretation of "Crossroads." The famously collaborative guitar player also invited one of music's brightest new talents, Taylor Swift, to appear on "Half of My Heart."