The Mastery of Music Theory series by Brian Kehlenbach is a comprehensive set of three volumes covering Fundamentals of Music (Book 1), Diatonic Harmonization (book 2), and Chromatic Harmonization (book 3). The format is presented as a text and workbook, providing explanations and examples of important concepts while also including worksheets that can be used for practice as well as homework assignments. The books are suitable for classroom use as well as independent learning.