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 . A perfect choice for beginning group or private instruction, the book/CD offers students a variety of styles and moods, and includes the "best ever" teacher accompaniments. The audio CD is playable on any CD player. For Windows and Mac computer users, the CD is enhanced so you can also access MIDI files for each song.