Following on to Brian's listserv post, I would like to add a few more points on periodisation. Although Kondratieff cycles or long waves do play a role here, the intention is not an in-depth discussion of the long wave theory. The intention is rather to create a foundation for a narrative that describes the second half of the 20th century as an interplay of economic, political, technological and cultural forces, seeking out turning points that allow to identify specific characteristics of techno-economic changes as an explanatory framework for specific cultural or artistic phenomena, such as participatory media and / or media art and technology practices.