Imagine the scene: You’re at church, belting out a hymn, and the sound is so joyful that you turn, smiling, to look around. You notice a spray of spit coming from the mouth of the person next to you: One particularly large droplet arcs toward the person in front, then lands, right on their neck.
Three months ago, you might have thought that moment was gross. Today, you’d probably find it frightening.
In the space of a few months, group singing has gone from being something life-affirming to a potential source of disease, even death. Outbreaks of the coronavirus have been linked with choir rehearsals and church services in Britain, Germany, the Netherlands, the United States, and, this month, South Korea.
Some countries have banned group singing as a result, and scientists are studying the risks. But with conflicting messages from the authorities worldwide, singers are left for now with little but anxiety.
To many scientists and doctors, the risk of singing is clear. “It’s not safe for people to simply return to the choir room and pick things up,” Lucinda Halstead, the president-elect of the Performing Arts Medical Association, said in a telephone interview.
William Ristenpart, a chemical engineer at the University of California, Davis, who has studied how disease-carrying particles spread during speech, said in a Zoom interview that he “would strongly agree with the assessment that singing, especially indoors in enclosed spaces, is a terrible idea right now.”
The most obvious reason singing is a risk for virus transmission is that droplets of saliva can spray from someone’s mouth, just like when they cough, Professor Ristenpart said. Those droplets can be made out of the mucus that coats the lungs and larynx, and could contain virus particles.
But a potentially bigger issue comes from particles you can’t see, called aerosols, he added. Those are so light that they travel “wherever the air currents take them,” Professor Ristenpart said.
“Think of it like smells,” he said. “If someone on the other side of your house starts baking chocolate-chip cookies, eventually you smell the chocolate aroma.” In a poorly ventilated room, aerosols would accumulate.
There is uncertainty over whether aerosols spread the virus, but Professor Ristenpart said outbreaks among some choir groups would suggest they had played a role, especially since the attendees in some cases said they had followed social-distancing rules.
Professor Ristenpart’s research has focused on speech, but other researchers are studying aerosol production from singing specifically. In May, members of the Bavarian Radio Chorus, a choir in Munich, took part in experiments organized by the Ludwig Maximilian University in which choristers inhaled vapor from an e-cigarette and then sang, so researchers could see the plume of aerosols that emerged and watch how it behaved. Matthias Echternach, the project’s lead researcher, said in a telephone interview that he hoped to reveal preliminary results this month.
Professor Echternach said his group had also looked at whether wearing a mask had an impact on how aerosols spread, as a potential — if hot and uncomfortable — way to minimize risk. The researchers have also studied the effects of wearing a plastic face shield, he said. A boy’s choir in Austria had started to rehearse wearing those, he added, but in his team’s experiments, the aerosols simply hit the shield, then spread out around it and into the room. “They’re meaningless,” he said. “Unfortunately.”
Governments and health authorities around the world have taken different approaches to turning this scientific advice into rules and guidelines. Health officials in the Netherlands, where more than 100 choristers became ill after a single concert in Amsterdam, have advised against all “joint singing activities.” In Germany, the rules vary by region: In some, choirs can rehearse with 10 feet between singers; in others, group singing is banned, including at religious gatherings. (When a church near Frankfurt ignored the rules on May 10, it led to a cluster of infections.)
In Norway, 50 people or fewer can sing together, as long as everyone keeps at least a meter, or three feet, apart. Just over half the country’s choirs have returned to practice, said Asmund Maehle, the secretary general of the Norwegian Choir Association, in a telephone interview.
In the United States, the question of whether and how groups can safely sing together is becoming more urgent, as states allow houses of worship to open across the country. In May, the Centers for Disease Control and Prevention issued guidance that churches should ensure choirs at services follow social distancing, revising previous advice that said they should “consider suspending or at least decreasing” singing in services.
The same month, Dr. Halstead of the Performing Arts Medical Association spoke on a two-and-a-half-hour long webinar co-organized by the association, which has been widely viewed and discussed among America’s choirs. In it, she was asked: “Can you imagine a safe way to have a rehearsal right now?” Her answer was blunt: “No, I can’t.”
She quickly clarified the comment, saying that if “it’s a small group and it’s outside and the wind is not at your back,” the risk of catching the virus while singing would be reduced. But she said that until there was a vaccine or rapid testing, no one should be returning to choir rehearsal as they had known it before the pandemic, with many of singers gathered in a room. A vaccine could be over a year away, she added.
Her comments sparked panic among some choirs and singing teachers in the United States — one podcast said comments in that webinar were a “death sentence.” But in a telephone interview, Dr. Halstead said people should realize changes to rehearsals would only be temporary, and that singing in small groups was still possible.
In the webinar, she had even given some examples of creative approaches to rehearsing and performing safely, she added: A local barbershop quartet in Charleston, where she lives, had been practicing outside with social distancing; a choir in Myrtle Beach, South Carolina, was singing in weekly streamed services by spreading out in an empty church.
“I know what I said made a lot of people depressed,” Dr. Halstead said. “For a singer, if they can’t use their voice, they’re completely disabled. It affects their self-worth, it affects everything.”
But, she added, “People have to be patient.”
“This is only temporary.” she said. “God understands you can’t sing right now.”