More than 20 years of research leads us to affirm, without any doubt, that the density of the cultural activities of a certain territory - among them those related to the performing arts - transform its capacity for development, and this is produced through the complex and sophisticated links between culture and the socio-economic system. These relations go much further than the simple economic multiplier effect that has already been reliably confirmed in numerous studies of festivals or stable theatre seasons. With more complex approaches, we have also observed transformative effects on social capital and its interaction with human capital, on the capacity for innovation and on the propensity for entrepreneurship.