In 1805, the world of music was startled by an avant-garde and explosive new work. Intellectually and emotionally, Beethoven's Third Symphony, the "Eroica," rudely broke the mold of the Viennese Classical symphony and revealed a powerful new expressiveness, both personal and societal. Even the whiff of actual political revolution was woven into the work-it was originally inscribed to Napoleon Bonaparte, a dangerous hero for a composer dependent on conservative royal patronage. With the first two stunning...