The Lesson Books are at the core of the Basic Piano Course and should be used as the basic instructional tutor for all students. To ensure problem-free progress throughout the course, and to avoid gaps that might impede progress, the authors have used "overlapping concepts." This means that after a concept has been introduced, it continues to be reinforced simultaneously with the introduction of new concepts. Use the Lesson Books in conjunction with the other core subject books, Theory Books and Recital Books, plus any supplemental books you feel will enhance your students' experiences at the piano.