Beethoven's foremost physical characteristic was his hair; four strands under recent chemical analysis revealed lead poisoning that could account for the abdominal distress, irritability, and depression that Beethoven suffered from for most of his adult life. But other physical, emotional, and spiritual problems were the result of a lifetime of struggle and frustration, which forced him to look inward and reinvent himself and, in so doing, reinvent the nature of musical expression in the Western world.