The history of any art in such a stage of reformation is necessarily complicated, and the history of music is in no way exceptional. A thousand new influences shaped it, hundreds of composers and of virtuosi came for a while to the front. Political, social and even economical and commercial conditions bore directly upon it. To ravel from this tangle one or two threads upon which to weave a consecutive narration has been the object of the editors. Minuteness of detail would have thwarted the purpose of this as of the first volume, even if space could have been allowed for it. The book has, therefore, been limited to an exposition only of general movements, and to only general descriptions of the works of the greatest composers who contributed to them. Many lesser composers, famous in their day, have not been mentioned, because their work has had no real historical significance. They will, if at all vital, receive treatment in the later volumes. On the other hand, the reader is cautioned against too easy acceptance of generalities which have long usurped a sway over the public, such as the statement that Emanuel Bach was the inventor of the sonata form, or that Haydn was the creator of the symphony and of the string quartet. Such forms are evolved, or built up step by step, not created. The foundations of them lie far back in the history of the art. In the present volume the attention of the reader will be especially called to the work of the Italian Pergolesi, and the Bohemian Johann Stamitz, in preparing these forms for Haydn, Mozart, and Beethoven.