He said Eurovision had developed into a giant production, with today’s over-the-top TV feast a world away from the first radio-focused Eurovision in a Swiss theatre in Lugano in 1956. There were seven competing singers and an orchestra.

Europe’s public service broadcasters “co-produce the biggest musical event in the world. If you had this idea today, you wouldn’t be able to start it,” said Stadler.

An expected 160 million to 200 million viewers will watch the final, while around 1.2 billion interactions on social networks are anticipated.

3D frame of light

Set designer Florian Wieder said the relatively small size of the arena — in Eurovision terms — meant the set could not be hung from the ceiling.