[giantg2]

Doesn't have to be wifi. There are many different ways to communicate. It's a matter of finding the best one. Unfortunately, the largest drawback is the potential for malicious/mischievous actors to interrupt them given the crowd. Something as simple as FM transmission, like at a drive-in, could be an option.

[singleshot_]

Could use Meshtastic maybe

[immibis]

this is probably why it never works - silly overcomplex ideas.

There's not even a need to create anything. Rent from a silent disco company. Done.

[singleshot_]

I think you may have a need to create a sense of humor. Perhaps you have heard about the Meshtastic talk at defcon by now.