"Égrégore" means an energy produced by the desires of many individuals in a common goal. This is the starting point of this audiovisual performance that aims to exploit the group movement phenomenas. Complex and expressive behaviors are generated and controlled by a computer and transcribed in sound and image. A crowd of particles deploys itself, reorganizes, blends into living structures more or less coherent, evolving from a chaotic movement toward a cohesive group. This project is a continuation of chdh’s work on audiovisual instruments, but aims to radicalize the search"