Tai Chi Changes is the long-awaited followup to Stuart Alve Olson's T'ai Chi According to the I Ching: Embodying the Principals of the Book of Changes. That book focuses on the 16-posture Yi Tai Chi form which is part of the 64-posture form taught in this work.These 16- and 64-posture arrangements are Yang Style Taijiquan forms based on the workings of the Book of Changes. The 16-posture sequence relates to patterns of movement according to the Eight Trigrams, while the 64-posture form relates to a unique organization of the 64 Hexagrams. Stuart collectively refers to this style of Taijiquan as Yi Tai Chi (Tai Chi Changes), with the 16-posture form's full title being the Before Heaven Yi Tai Chi Form and the 64-posture form as the After Heaven Yi Tai Chi Form.Along with the descriptions for each count (or part) of a posture, the book includes photos showing the hand and arm positions as well as foot diagrams that provide a top-down view of the specific Taijiquan stance, the direction the body faces at the end of each count (in the highlighted trigram image), and which foot is carrying the weight (indicated by a white dot in the foot icons). Seeing the diagrams along with the photos of Stuart Olson are extremely helpful, not only for learning each posture but also to have as a quick reference guide for any particular section of the form. The posture photos and diagrams add to the instructions by showing stances and arm positions without having to constantly repeat such details in the text. At the end of each posture is a comprehensive chart diagramming every count in the After Heaven Yi Tai Chi Form. Just from the posture photos, foot and stance diagrams, and the posture summary charts, a great deal of detailed information is available for long-term study and mastery of Yi Tai Chi.Serving as the foundational work and source book of the entire Yi Tai Chi system-which Valley Spirit Arts teaches through online courses, workshops, and private lessons-Tai Chi Changes is as much for beginners as it is for the more advanced students of Taijiquan. All readers will acquire a great deal of information.