Science‘s COVID-19 reporting is supported by the Pulitzer Center and the Heising-Simons Foundation.
As U.S. schools and colleges debate how to reopen amid the novel coronavirus pandemic, band directors and musicians are wondering when—or whether—music can be played safely. A new study finds that while musical instruments do generate airborne particles that could carry SARS-CoV-2, the risks for performers and audience may be manageable.
There is almost no research on whether musical instruments produce the airborne particles—or aerosols—that can transmit the novel coronavirus. So it’s impossible to know whether keeping 2 meters away is enough to stay safe from a trumpet at full blast.
Without data, schools were already cutting band rehearsals “out of fear,” said Mark Spede, president of the College Band Directors National Association. Given the potential threat to music education and the livelihoods of musicians around the globe, Spede’s group and the National Federation of High School State Associations raised about $275,000 from more than 100 arts groups to study the safety of performing during the pandemic.
Researchers at the University of Colorado, Boulder, had five student musicians–a soprano singer and clarinet, flute, French horn, and trumpet players—enter a clean room one at a time. The room was normally used for indoor air pollution research, and it was outfitted with tight seals, and multiple high-efficiency particulate air (HEPA) filters remove almost all particles from the air.
The participants performed a short solo piece with a wide range of high and low notes and different styles of playing, including a smooth chorale and a staccato march. The players angled their instruments’ openings toward a series of tubes that feed into a trio of particle monitors that detected aerosols of different sizes. An imaging system also captured the airflow around the musicians to visualize where the particles moved.
The initial results—which were released online this week without peer review—showed for the first time that the instruments can produce aerosols in the range of sizes that can carry the COVID-19 virus. These aerosols can also stay airborne for long periods of time, and different instruments produced different amounts. For instance, the trumpet and clarinet, which run straighter from the mouthpiece to the instrument opening, had higher concentrations of aerosols.
To reduce the spread of aerosols, the researchers tested instrument covers, such as a cloth covering for the opening or a sack covering an entire clarinet; both effectively reduced aerosols, in some cases by half, without deadening their sound.
Another team at the University of Maryland, College Park, used computer models to examine whether an infected musician might spread the virus in different conditions. The modeling confirmed the importance of distancing to avoid infected plumes. It also suggested that conventional ventilation systems, where air supply and exhaust are both on the ceiling, are less effective than those in which the exhaust is on the floor.
The results add to recent work on airflow from instruments. A study in May had Vienna Philharmonic wind and string musicians play after inhaling a mist that is illuminated by headlights when exhaled. Another study, conducted this spring in Germany, tracked air flow from wind instruments. Both found that instruments produced less airflow than singing (although flutes produced more than other wind instruments).
Bernhard Richter, an otolaryngology specialist and co-director of the Freiburg Institute for Musicians’ Medicine, who led the German study, says his team’s initial results could inform safety recommendations. And he says the new aerosol work will offer even more sophisticated data. “We don’t know enough about aerosols … and the critical issue of how they are spreading.”
The researchers behind the aerosol study will now gather data from additional instruments, singers, dancers, and actors. Those could give a fuller picture of potential risks of performance and improve computer modeling on the effectiveness of distancing and air circulation, says Shelly Miller, an engineering professor at the University of Colorado, Boulder, who helped run the study.
Based on the initial findings, the organizations that funded the study recommend that indoor rehearsal rooms and performance venues use HEPA filters and increase circulation, and that musicians use instrument covers. They also recommend 2 meters of distancing and that performers face the same direction, which could limit band or orchestra size.
Miller says she hopes further data recommendations will let the band play on. “It’s heartbreaking to halt these activities because we don’t know if they’re hazardous or not.”