Undoubtedly the Seventh Sonata is a fascinating piece. It is perhaps the most complex Sonata to perform; superimpositions of polyrhythmias in the same hand, sudden "climatic" changes, technical complexities in certain steps... Already in the previous Sonata the musician had abandoned conventional tonality to draw definitively his compositional habitat with his mystical chord which here becomes a container element and producer of the whole. In this work we see how the writing is enormously complicated compared to the previous Sonatas but this does not confuse the listener; I would say that this density of notes is the indispensable voice, necessary to perfectly describe both the environment and the development of the story ofwhich the composition speaks. Writing that then, as we will see starting from the Eighth Sonata, will go towards a gradual simplification, almost dematerialization if we think of the incipit of the Tenth Sonata Op.70.