The Musiktheater im Revier in Gelsenkirchen, an architectural masterpiece by the architect Werner Ruhnau, who died in 2015, is regarded as one of the most innovative cultural buildings of the postwar years. In this publication, Anita Ruhnau reports on the time when it was created from a very personal perspective. Her memories hence provide lively insights into the art scene of the 1950s and 1960s. She tells, for instance, of the first encounters with Norbert Kricke and the then still totally unknown artists Yves Klein and Jean Tinguely, and of experiences with Arman and Christo. Letters, up to now unpublished documents, and private photos portray the unique collaboration and the life together of all the individuals involved in the building of the theater.