In this paper I try to outline a model that can bring out the meaningful relationships between ‘the instrumental’ and ‘the electronics’ in mixed music. The model is based on the semiotic square which is considered in semiotics as a powerful conceptual framework to examine the relationships between two terms (S1/S2) and their negative (non-S1/non-S2), terms which can be characters, situations, actions, concepts, etc. Two paradigmatic axes represent the relations between the actors of mixed music: the sources (instrumental and electronic) on the one hand, and the manipulations (real-time processing and sound projection) on the other. According to the semiotic square, the relations inside the environment are defined in terms of contrariety, contradiction and complementarity. This model allows us to start out with a purely technological description of the ‘mixed music’ genre and of individual pieces, with the advantage of a pre-operative analysis of the system. It describes the immanent structure of the environments and releases the potential interactions between the instrumental and the electronics of mixed music. These interactions are examined, from a paradigmatic point of view, with numerous representative pieces of mixed music from the twentieth century.