Pop singer / songrwriter John Mayer announced on Friday he is canceling his scheduled spring tour because a throat condition is still bothering him.  Mayer postponed the release of his upcoming fifth album about six months ago after being diagnosed with granuloma, and the condition has apparently not healed, the singer said.  The album, "Born and Raised," is slated to be in stores on May 22nd, but the ensuing tour will have to wait until Mayer heals.  No timetable for the tour to be rescheduled was announced.  CHeck out the cover art for "Born and Raised" below.