Book 4 in this series introduces new concepts such as: new time signature 6/8 ; relative minor scales; key signatures for major and minor scales; primary triads and the dominant 7th; subdominant and dominant 7th chords; authentic, plagal, and half cadences; among others. Students are presented with a final test at the end of this book to demonstrate their knowledge of concepts presented in this level. Includes audio tracks to reinforce every unit, which can be used at home or at the lesson.