Mr. Piston's primary concern is to provide an understanding of the common practice of composers, in matters of harmony, as observed in music of the eighteenth and nineteenth centuries. Among the special features of the book are the author's treatment of the question of harmonic rhythm, and his simplification of the principle of modulation. He places emphasis on the construction of harmonic phrases, rather than on the harmonization of given melodies, as the most important kind of exercise, although both are included in the written problems for the student's performance. Walter Piston is Emeritus Professor of Music at Harvard University and has twice received the Pulitzer Prize in Music. The work of this eminent composer is regularly being performed by the leading orchestras and chamber ensembles both here and abroad.