You are about to embark on a course of study designed to give you, in the shortest possible time, a complete understanding of the principles of modern harmony, improvisation, and dance band arranging. The Berklee Correspondence Course was first developed in the 1950s as a way to teach students at a distance - a precursor to today's Berklee Online. In those days, a student would receive lessons by mail and send their assignments back for grading by Berklee faculty. This book is an update of the 1971 edition. It features an answer key to many of the activities available online by accessing the unique code found on the first page of the book. The actual lesson material, together with the comments and suggestions of your personal instructor, should combine to provide you with a comprehensive knowledge of the techniques of modern music and jazz, in practice as well as in principle.