The 15th episode of Darmstadt On Air is hosted by a new composition tutor of the Darmstadt Summer Course: Sarah Nemtsov. She invited the set designer Sebastian Hannak to be her conversation partner in this podcast. At the opera house in Halle he created „Raumbühne Heterotopia“ in 2017, a 360° stage installation conceived as a music-theatre-city where the borders between audience, orchestra and performers are blurred for the benefit of an immersive spatial experience and emphatic „Totaltheater“. In more than ten different formats such as opera, drama, dance, performance or concert, the space can be experienced from totally different perspectives. Sebastian adapted his Heterotopia stage for several theater and music theater productions like Sarah’s opera „Sacrifice“ (2016). That was when the two artists met in Halle some years ago. He started to work on his set design when he only knew parts of Sarah’s music. Maybe more than ever before he was forced to invent reality for a piece on stage. For both of them theater is an extraordinary moment of transition.