Taking into account the drastic over-use of the term "interactivity" in connection with new media, this anthology is designed to scrutinize the preconceptions that surround the idea of human-computer interaction. German media theories of agency, algorithmic semiotics, interfaciology, mediality, performativity, and transcriptivity are combined with international artistic and technological investigations including interactive audio programming as well as robotic and artificial life art. Several essays give an overview of interactive music and sound performances, which up to now have rarely been discussed.