This book provides first-year university students majoring in western art music with a thorough study of both structural and ornamental diatonic harmony in the Common Practice Period (c.1700 until the late 1800s). It provides one of the most comprehensive coverages of the topic of ornamental diatonic harmony published to date, and offers ample musical examples to illustrate the concepts explained, as well as exercises in creative four-part writing, analysis, aural development and keyboard harmony to practice the application of these concepts. Understanding the difference between the way chords act at the structural level and the ornamental level explains why rules that apply to one do not necessarily apply to the other, providing novel insights into the interplay between harmony and melody and renewed appreciation for the ingenious ways in which composers throughout the Common Practice Period exploited these techniques.