Systems of Decimal Octave Evolution

Across many schools of thought and programs of personal development, the octave emerges, as do decimal sets. Gurdjieff and Ouspensky expose to us the musical cycles of seven notes punctuated by two "shocks" that serve as both commas and pivot points, and returning to the origin at the end. The Tarot mirrors this rhythm and musicality in its suits. These other systems seem to map as well. (It could be that finite sets of elements reach a ceiling of complexity at about ten, when we run out of fingers, beyond which we have rarely conceived of any further layers of dynamics.)