Tech N9ne Performs at a Packed Concert at Lake Ozark, MO - TMZ

so it was definitely a special occasion to have Tech come out and perform.

That didn't seem to bother Tech N9ne though -- ditto for the concert promoters and the hotel folks hosting the event.

Aside from the bad idea of hosting any type of large gathering like this -- indoors or out -- the fact Tech N9ne is in the mix here seems to signal something else that's fairly troubling ...