More than 4,000 concertgoers in Germany attended a coronavirus experiment over the weekend to understand how the virus could be prevented from spreading at large indoor concerts.

The attendees at the Tim Bendzko (pictured) concert in Leipzig on Saturday morning were equipped with tracking devices on chains around their necks that transmit a signal at five-second intervals and bottles of fluorescent disinfectant.

The hand sanitiser shows up under UV lights, which the scientists used to look at after the concert to see surfaces where a transmission of the virus through smear infection is most likely to take place.

The University Hospital of Halle’s RESTART-19 transmission risk assessment collected data on each person’s movements and proximity to other members of the audience at the indoor venue.

The project’s organisers say the aim is to “identify a framework” for how larger cultural and sports events could be held “without posing a danger for the population” after September 30 when COVID-19 measures change.

The 12,000-capacity Leipzig concert hall, where the experiment took place, modelled three different scenarios with changes to the number of entrance points and capacity.

The first saw the volunteers entering through two main doors before taking their seats, while the second “optimised” scenario saw the crowd enter through eight entrances to facilitate less mingling, and every second seat on the stands was blocked.

In the third, only 2,000 spectators were allowed to enter the venue and be seated at a 1.5m distance from each other.

Volunteers aged 18-50 worse masks and were required to pass a coronavirus test in the two days prior to the event. They also had their temperatures checked prior to entering the arena.

Researchers will also monitor what role vapours play in the spread of COVID-19 by using fog machines.

The scientists behind the concert said they plan to present their findings in early October.

Image: Raimond Spekking / CC BY-SA 4.0 / Edited for size