Book excerpt: Focusing on the manuscript sources for one of Beethoven's most popular piano sonatas, the OP.57 in F minor (known as the "Appassionata," 1804-5), this book presents transcriptions of all the known sketches for this work and evaluates them in terms of their specific stage of evolution and their relationship to the final version. Incorporating the analytic vocabulary proposed by Jan LaRue, Frohlich summarizes salient points for each movement which serve as a basis for the sketch discussions. The detailed sketch analysis explores such topics as harmonic rhythm, phrase structure, and climax planning. Facsimile reproductions of the sketches allow scholars to compare the transcriptions with the originals. Also included is an examination of the significant revisions of the finale in the autograph.