I listened in to a webinar from New Jersey. The preliminary results from a research by the University of Colorado were released. The full presentation can be seen here. https://www.nfhs.org/articles/unprecedented-international-coalition-led-by-performing-arts-organizations-to-commission-covid-19-study/
Singing and recorder data will be released by the end of the month.
So far the preliminary suggestions for some wind and brass instruments are. More tests are being done
Masks should be worn by all students and staff prior to entering the performing arts room. Masks should continue to be worn until all students are seated and ready for instruction (example, long rests, sectional work, moving around the room, etc.)
No talking should occur in the room without a mask being properly worn.
When possible a mask with a small slit for mouthpiece access should be worn while playing.
In instrument groups where a mask cannot physically be worn the mask should be worn over the chin and replaced during periods where the student is not playing. No talking without a mask.
Social distancing should occur as suggested by the CDC.(Centre for Disease control ) Currently that distance is a 6×6 foot space around each student with the student sitting in the center. This may reduce the number of students that can fit in a performing arts classroom. Straight lines should be used as curved setups can affect the aerosol movement in a room.
Students should sit all facing the same direction, back to front to minimize potential exposure.
Trombones should have an additional three feet of distancing making their space 9×6. The player should be seated three feet in front of the back line, leaving an additional six feet in front of them due to the extended nature of the instrument and slide that can be in extended position.
Spit valves should not be emptied on the floor. Recommend using a puppy pad (or similar) to catch the contents of the spit valve and discard.
Masks and nylon bell coverings all reduce particle concentration
Richard Jones Music Education Blog 