Essentials of Music Theory is designed for students of any age, whether listeners or performers, who want to have a better understanding of the language of music. In this all-in-one theory course, you will learn the essentials of music through concise lessons, practice your music reading and writing skills in the exercises, improve your listening skills with the available ear-training, and test your knowledge with a review that completes each unit.  The Teacher’s Answer Key is a spiral-bound book that includes answers for the Lesson and Review pages as well as music for the Ear-Training pages in Volumes 1-3 of the Student Books.