The Theory section in Book Three begins with a review of the theory concepts introduced in Book Two Book Three before introducing more advanced time signatures; major, minor, augmented and diminished triads; and minor chords, chord progressions and harmonizing melodies. By the end of, students will be composing short melodies, and will have a fundamental understanding of the building blocks of Western music.

Ear Training pages with aural exercises are again applied throughout Book Three, incorporating the knowledge gained in the steadily advancing lessons and putting it immediately into practice.

The History section of Book Three continues to deepen the connection among all aspects learned throughout the series, putting music into perspective with social and political events and progressions within all the arts. Book Three also includes a colorful comprehensive timeline including all composers and performers studied, thus providing quick reference and motivation toward further study.