""4 The Need of a New Musicography for the Blind""""5 Proposed Methodology""; ""6 Conclusions""; ""References""; ""Group Theory for Pitch Sequence Representation: From the Obvious to the Emergent Complexity""; ""1 Introduction""; ""2 (L(Sn), أ‚آ°)""; ""3 Piph Music for Algorithmic Composition""; ""4 Translating a Piece of Music into a Single Number""; ""References""; ""Mazzola's Escher Theorem""; ""1 Basic Concepts""; ""2 The Category of Gestures""; ""3 Hypergestures with an Approach to Escher's Theorem""; ""4 Topological Categories and Mazzola's Escher Theorem""; ""References""