After having read and reread Rosen's "The Classical Style" and "The Romantic Generation" many times, I had very high hopes for this new book. Unfortunately, it did not live up to my expectations.
First of all, it is much too short. At only 141 pages, Rosen simply does not have space to discuss his subject in much depth. Secondly, there is little that is new in this book. Many of the musical examples he discusses in this book are analyzed much more thoroughly and satisfyingly in his earlier works, and many of his insights into how the expression of emotion through music has changed over the centuries can also be found in a more fleshed out form in his other books. The proportions of the book also reveal that Rosen is mostly writing about music that he has already written a lot about: one chapter on Baroque music, three chapters on Haydn, Mozart, and Beethoven (the composers most discussed in "The Classical Style" and "Sonata Forms"), one chapter on the early Romantics (Chopin, Liszt, and Schumann, half of the composers discussed in "The Romantic Generation"), and one chapter on everything after them.
I also find that this book is simply not as well written as his others. While some may prefer Rosen's less dense and formal style in this book, I think that some of the rigor that is so key to his insights is lost. The book is also filled with contradictions and arguments with other music scholars over technical details. While such elements are not always bad provided that they are a source of insight, I did not find them to be so in this book. I suspect these problems may arise from the fact that this book was created from a series of lectures given by Rosen at the University of Indiana at Bloomington. While these chapters were probably wonderful lectures for the university students, I don't think they come together to make a convincing book.
Most disappointing, though, is the fact that he doesn't even write that much about emotion in music. Mostly, this book is an analysis in the way localized phrase structures evolved from the baroque through the early romantic period. In general, Rosen discusses only snippets of music, and refuses to address how large scale form contributes to the emotional impact of music. For me, much of the power of classical music comes from the way it can take me on a journey through many different emotions and thus create a sense of narrative drama. A refusal to discuss how different parts of a piece combine to create this sense of narrative is to me a refusal to discuss perhaps the most important way composers communicate emotions through music.
Charles Rosen's "The Classical Style" and "The Romantic Generation" are the best books on music that I have ever read, and I urge any lover of classical music who has not read them to do so. This one, however, you can skip.