Poet Rita Dove wrote a book about Beethoven, his best friend in 1803, and the piece they premiered together. Beethoven wrote an astonishing sonata inspired by the virtuosity of violinist George Bridgetower. But one night over drinks, the two friends got into a fight. Beethoven took Bridgetower's name off the music, and they never spoke again. Rita Dove has re-imagined their relationship in her book, "Sonata Mulattica." She joins PT host Fred Child to guide us through their story, and through the piece that's become known as Beethoven's Kreutzer Sonata.