Urban Metabolism: Der Mond is a cybernetic performance and sound installation that recontextualizes the sociological framework of Urban Metabolism into the domain of electroacoustic improvisation. The work reclaims a discarded industrial object in the form of a rusted metal plate found on the streets of Berlin transforming it from linear urban waste into a resonant generative feedback system. The instrument exploits mode coupling and structural fatigue to create nonlinear acoustic interferences governed by a custom auto mutation algorithm based on cybernetic homeostasis.