Abstract: This research investigates the interaction in music that combines electroacoustic and instrumental resources in a performance - mixed electroacoustic music. Due to the presence of different technologies in the performance and composition of this repertoire, "interaction" can refer to the relationships between performers and technologic resources. Nevertheless, it also can refer to the relationships between the sounds we perceive in the listening experience. We distinguish these two ambits, practical-technological and sound-morphological, and investigate their interrelations in order to focus on the second one. Then, we investigate, independently of the technological resources used, the relationships and interactions between sound streams. Through a listening process, the sound events are grouped in layers, plans or streams and constitute a texture, the same way the notes are grouped in a voice in tonal counterpoint. The main problem of this research concerns the way that these streams interact in mixed electroacoustic music considering its particularities. We identify theoretic tools from a bibliographic revision to investigate and describe how the streams are constituted, distinguished, how they relate to each other and how they relate to the visual aspects of performance. We apply these identified tools in the analysis of four mixed pieces in order to verify specific strategies found in the repertoire. Moreover, we present a personal experience of composing two pieces in interaction with the research. This research proposes a theoretic distinction between micro-texture and macro-texture, discusses the theories concerned to interaction, argues about the plausibility to consider the visual aspect a textural element in interaction with sound, and evidences the ambiguity and fluidity present in visual and sound relationships in this repertoire. Keywords: composition, interaction, mixed electroacoustic music, sound streams.

This paper analyses interaction in mixed electroacoustic music through the perception of streams in the listening experience. The interaction between acoustical instruments and electroacoustic resources is observed in a wider theoretical scope: the interaction between streams perceived in listening. The study investigates issues related to the characterization of streams, how we perceive their interaction, and how we can describe this interaction for analytical or compositional ends. For this, two central concepts are revised: Dennis Smalley’s behavior metaphor and Trevor Wishart’s counterpoint idea. We present a brief analysis of selected electroacoustic mixed works by Karlheinz Stockhausen, Cort Lippe, and Tristan Murail to better illustrate listening aspects of interaction in this repertoire.

This article discusses the collaborative process used in the creation of Chão de Outono, for flute and electroacoustic sounds. Through an analytical report, we aim to understand the importance of the collaboration between performer and composer for the definition process of sound elements and their morphological stability (COSTA, 2009).

The present research is an investigation of the relations between French semiotics and musical composition in the compositional process of a piece for accordion and piano. Based on the proposal of a process that uses the concept of the generative trajectory of meaning as a tool for compositional decisions, I try to make a cross between these areas. The generative trajectory of meaning consists of three levels with different degrees of abstraction: discursive, narrative and fundamental, through which the semiotic analysis takes place. The apprehension of meaning in a text (verbal, non-verbal or syncretic) starts from the most complex and concrete level (discursive) to the most simple and abstract (fundamental), while the production of meaning goes the reverse way. In the compositional process of the piece, the first movement focused on issues concerning the fundamental level and the second focused on issues relating to the narrative level. It is a practical application in composition that involves a reciprocal activity in which, at the same time, the meaning is generated and apprehended. The monograph points to possible future applications through the elements of a compositional theory sketch.