Open-air Concert on Tower Block Roofs: “Himmel über Prohlis”, Dresden

Musicians and orchestras are among those for whom, for the foreseeable future, the corona pandemic means "abandoning familiar performance formats, orchestra sizes and audience constellations. However, the forced realignment also presents an opportunity to devise and try out totally new formats." That was the premise of the Dresdner Sinfoniker (Dresden's symphonic orchestra) – and it gave birth to the "Sky over Prohlis" programme, which in many ways represents new territory for musicians, the audience and us as providers of technical services.  The composer Markus Lehmann-Horn wrote a piece for 16 alpine horns, nine trumpets, four tubas and dagu drums, which was not to be performed in a concert hall but was intended to ring out from the roofs of a tower block estate in the Prohlis district of Dresden. The audience enjoyed the music from their balconies, at open windows and on a parking deck; they were sitting in the "royal box" so speak, as artistic director Markus Rindt put it. With all social distancing and hygiene rules being observed by both audience and orchestra, works by John Williams, Giovanni Gabrieli and Minxiong Li also rang out in addition to Lehmann-Horn's premiere – a sensory concert experience that the people of Dresden could enjoy in their homes.

Both orchestra and technical planners were faced with challenges: the sound of the instruments was to ring out from the roofs of five different tower blocks at a height of around 17 metres as well as from a parking deck – whereby the distance between them was between 50 and 450 metres! This meant the some of the musicians had to start playing with a slight delay so that the sounds reached the audience in harmony all at the same time. The solution was a so-called "click track", an idea developed jointly by Volker Greve, the members of the Dresdner Sinfoniker and us. This gave each musician in the orchestra his or her cue, with each receiving their individual metronome on their headphones via wireless connection with delays of varying length. The musicians furthest away had no delay because the sound from their instruments reached the audience last, whereas the nearer instruments – the dagu drums on the parking deck for example – came in later.

On the day before the open-air concert, the headphone mixes were set together with the musicians and saved accordingly. We also designed and implemented an appropriate P.A. system to ensure a perfect auditory experience.

The unusual concert was a complete success and met with tremendous acclaim from audience and media alike. "Sky over Prohlis" was intended as a pioneering venture and as an example of how unusual sound experiences can reach a broad audience under pandemic conditions – thus making a stirring contribution to a new start for the future of music.