This topic started over here with a list of important facts and issues related to singing and the spread of COVID. We have continued it below with examples of how to "sing" without becoming "super spreaders."
Safe Ways to "Sing" with Kids in the Time of COVID
For children's ministry, here are several ways you could potentially lower the risk of "super-spreading by singing" while still be able to include the power and pleasure of "singing" God's praise when we're safely back together. Some of these suggestions also apply to adult worship. Consult your denom's recommendations.
All of the following suggestions assume you have all your other safe-practice ducks in order.
1. Sing outside where the science of sunlight, air circulation, and increased distance can work for us.
Project or display lyrics.
See the non-singing suggestions below.
And... continue to wear masks.
And... continue to maintain appropriate distances,
And... continue to clean surfaces (including microphones)
2. Use Movement and Motion instead of voice to "sing."
Not only is this a technique many children's leaders are familiar with, it opens up learning opportunities when students discuss what movements best interpret the lyrics.
Not all joyful noises require an open mouth. 
3. Hum instead of sing, or use rhythm instruments
And... continue to wear masks.
And... continue to maintain appropriate distances.
And... continue to clean surfaces.
4. Quiet Your Singing and Speaking
Have kids whisper or sing softly (kids will like this) while continuing to wear masks and keep an appropriate distance. Make sure leaders don't have to shout.
Researchers warn that the constant and forceful expulsion of droplets during singing and speaking loudly in confined space risks "super spreading" (allows one infected person to infect others in mass by forcefully spraying droplets).
If you are the leader, song leader, or speaker, stand back from people, use your “inside voice” as our moms used to say, and use a microphone (and don't forget to clean it afterward).
5. Move singing to an online "sing-along" format.
Let's all pray for the day when these become "just" creative ideas instead of creative necessities.