"Right now, on a Saturday night, where is there an all-ages music show going on anywhere in the US where the kids in the pit are 14, 15 years old and no adult knows or cares that they're there?"

I used to go to those kinds of shows in my late teens. For what it's worth, I mostly am out of that because a) I like calmer music and b) the kids should have their own space.

But that doesn't mean that I don't run into small all-ages punk shows. There's usually one going on in Durango, CO a couple weekends a month that I have seen. I'm certain that in larger places the same thing is happening even though I don't know about them.

Consider that older folks not knowing about the show is kind of the sine qua non of what you're looking for, so I am no surprised that I, an "older folk", don't know about them.

But I know enough to know they are there. It's easy to find new music if you're looking for it.

Maybe go read or review Hesse's "Journey to the East" if you want a longer version of what I am getting at.