Louis Armstrong is widely known as the greatest jazz musician of the twentieth century. Offstage he was witty, introspective, and unexpectedly complex, a beloved colleague with an explosive temper whose larger-than-life personality was tougher and more sharp-edged than his worshiping fans ever knew. Terry Teachout has drawn on a cache of important new sources unavailable to previous biographers, including hundreds of candid after-hours recordings made by Armstrong himself, to craft a sweeping new narrative biography.