LEIPZIG, Germany — One of Germany’s largest venues roared back to life over the weekend, after nearly half a year of pandemic-induced hibernation.

Room-shaking bass rippled through a shoulder-to-shoulder crowd illuminated by stage lights, as German pop singer Tim Bendzko, backed by a black-clad band, sang his way through what under different circumstances would have passed for an ordinary set.

But during the pauses or singalong moments, an odd sound filled the silence: hundreds of voices trying to sing or cheer through tightly fitted masks.

The 1,400 or so people who attended the concert, one of the largest indoor gatherings in Germany in months, were not breaking any rules. In fact, they were the subjects of a study by researchers at Martin Luther University of Halle-Wittenberg, a public institution, to gather data on crowded indoor events during the coronavirus pandemic.

“It was weird with the masks,” said geography student Jonas Spiegel, 23, during a break, his face red from heat and exhaustion.

The aim of the study, researchers said, was to identify approaches that could allow concerts and other events to resume safely, before the emergence of an effective vaccine. Participants, all of whom had tested negative for the virus, were hooked up to tracking devices.

“I hope that this study will help to keep the joy of life up around the world,” said Michael Gekle, dean of Martin Luther University Halle-Wittenberg’s faculty of medicine.

The researchers said they received hate mail and faced questions over the safety of participants, along with concerns that the event could put the eastern city of Leipzig, which has seen comparatively few infections so far, at broader risk. Organizers aimed for 4,000 participants, but less than half showed up.

But Gekle and his colleagues maintained the safety measures were sufficient.

Germany has recorded far fewer coronavirus cases per capita than the United States and other hard-hit countries, but case numbers have begun to rise again. Over the past week, the country has reported 10.5 new cases per 100,000 residents — more than twice as many as two months ago. Since the pandemic began, Germany has seen more than 235,000 confirmed cases and more than 9,000 deaths.

It remains to be seen if Saturday’s simulation can make a substantial contribution to the drive to restart events. But the idea of inviting a large crowd into a confined spaced under controlled conditions has already inspired other scientists around the world.

Stefan Moritz, who headed the experiment, said he was aware of three similar projects being planned or pondered in Australia, Belgium and Denmark in response to the Leipzig test. The experiment may also spark similar efforts by private companies or sports teams. German Bundesliga soccer club Union Berlin announced last week it had applied for permission to host a test game with 3,000 fans. Under the club’s proposal, a negative coronavirus test requirement would replace social distancing rules in the stadium.

Even though Saturday’s experiment simulated a concert, the idea was driven by the economic woes of a local Leipzig handball club that hosted well-attended matches in the arena before the pandemic. Club officials fear that the lack of (or too few) spectators could drive them and others into bankruptcy, even though matches themselves have largely resumed.

Many venues face a dilemma: Events with a few well-spaced spectators may not be profitable, while more crowded events may risk exposing participants to the coronavirus. Finding a balance was a goal of Saturday’s research.

To identify high-risk practices, the Leipzig concert researchers looked at three scenarios.

In the first, participants pretended the pandemic did not exist. No social distancing. An auditorium at full capacity.

In the second, organizers imposed light social distancing rules. In the third, they imposed stringent distancing.

While the first scenario was the closest to a pre-pandemic concert, it appeared to spark the least enthusiasm.

Before entering the concert, Spiegel said he was “not nervous.” But as he left, he said he “would have been very scared” if not for the negative test results.

Hundreds of participants squeezed through a crowded exit, only to find a long line at the sausage stand outside. As the crowds lined up for free cake, sausages and drinks, researchers recorded their behavior.

They were studying whether “directing the people, where they enter and leave,” could reduce transmission risk, Gekle said.

Attendees were given bottles of disinfectant, mixed with a dye that becomes visible under ultraviolet light, to help researchers identify high-risk surfaces.

Though the beer was alcohol-free, the crowds appeared to loosen up as the day went on.

Despite orders not to get up from their assigned chairs during the more socially distanced afternoon segments, some stood and danced — cautiously at first, less so as their ranks grew.

“We got the feeling of a concert,” said Jana, 37, a participant who would only give her first name. “The main problem is breathing through the mask."

For singer Bendzko, the experience inspired optimism. “For us as a band, the performance was a surprisingly nice experience. Surprising, because we assumed it would feel a bit more sterile,” he said.

But he cautioned against unrealistic hopes for the resumption of entertainment as usual. “We are all called upon and need to make some compromises,” he said.

Karsten Günther, the head of the local handball club, said when the arena came back to life he had “wet eyes” as he watched “the lights flash again onstage and the feeling of normality return a bit.”

“If we’re not careful, we’ll never see this happen again,” he said.