The All-In-One Piano Lessons Books A, B, C, and D combine selected pages from the original Piano Lessons, Technique, Solos, Theory Workbook, and Practice Games into one easy-to-manage book. Book D is the equivalant to the second half of Book 2. A perfect choice for beginning group or private instruction, the book/online audio offers students a variety of styles and moods, and includes the "best ever" teacher accompaniments.