Representation of topoi by topological spaces The topos of music. Geometric logic of concepts, theory, and performance. In collaboration with Stefan Göller and Stefan Müller. Contributions by Carlos Agon, Moreno Andreatta, Gérard Assayag, Jan Beran, Chantal Buteau, Roberto Ferretti, Anja Fleischer, Harald Fripertinger, Jörg Garbers, Werner Hemmert, Michael Leyton, Emilio Lluis Puebla, Mariana Montiel Hernandez, Thomas Noll, Joachim Stange-Elbe, Hans Straub, Oliver Zahorka. With 1 CD-ROM 