John Clayton Mayer (born October 16; 1977) is an American singer-songwriter. Originally from Connecticut; he attended Berklee College of Music before moving to Atlanta; Georgia; in 1998; where he refined his skills and gained a following. His first two studio albums; Room for Squares and Heavier Things; did well commercially; achieving multi-platinum status. In 2003; he won a Best Male Pop Vocal Performance Grammy Award for -Your Body Is a Wonderland-.Mayer began his career performing mainly acoustic rock and pop; but gradually began a transition towards the blues genre in 2005 by collaborating with renowned blues artists such as B. B. King; Buddy Guy; and Eric Clapton; and by forming the John Mayer Trio. Half of My Heart is a song by American alternative rock singer John Mayer and American country pop singer Taylor Swift. It is the third single from Mayer's 2009 album, Battle Studies. "Half of My Heart" debuted at twenty-nine on the Billboard Hot Adult Top 40 Tracks chart on the issue date of May 8, 2010. This makes John Mayer's fourteenth appearance on that chart. The single also peaked so far at twenty-five on the Billboard Hot 100 chart.John.