Sing Along

If I understand correctly, you'd like remote participants to all participate in the sing-along from different locations over Zoom. If you are broadcasting a sing-along over Zoom with all participants in one location (one computer) and just allowing others to listen/watch, disregard my response below entirely!!

While there are some workarounds that may help you get closer to the desired result (Live Performance Mode / Original Sound for Musicians for all users + headphones for all users to avoid feedback), Zoom is designed as a conferencing product and painstakingly engineered to not allow large numbers of voices to be heard at the same time over a call.

I would advise looking for a software solution built for this task. If you find one, it will absolutely require all users to have audio input/output configurations that prevent feedback from occurring (headphones are the lowest common denominator).

One example is https://jamkazam.com/ , although I have never used and cannot recommend personally.