The best part about what I do is that this counts as research!
Yup... I'm up at 07:00 and "working."
I sometimes bring kids onto the stage to have 'em dance and even to sing along. We don't usually give them big instruments to play, though I've done that in the past. There's just too many chances of it going sideways.
But, we have tambourines and maracas on stage - and even have a handbell. We'll let 'em clang away with those and this gives the audience a reason to be happy and cheer. It also makes the parents proud, the kid excited, and part of the band can be doing stuff like switching instruments while we get 'em up on the stage.
If you're curious, you can choose to give them instruments. The audience doesn't usually mind (and quite likes it) but it will vary a whole lot with things like the style of music you play, the venue you're at, or the type of audience you have.
As a general rule, I don't suggest it - but it gets done. Once in a blue moon, someone from the audience will yell out that they can play the song and we'll invite them onstage and let them have some fun with it - but that's really rare. Usually, you're more likely (with us) to get invited on stage to sing with us. But, those are pretty rare events.
If you're in a band and decide to this, then you probably only want to do it only when you have a person dedicated to the audio engineer role. The person doing sound can just turn the volume down from the booth. Many bands don't have a person in that role, so you're kinda stuck with an awkward situation if it turns out they can't actually play or sing very well.
Anyhow, we frequently get the audience involved and, as of late, we've had a few shows where it was appropriate to invite a kid (not the eldest hoodlum, this is different situation) come on stage to sing or dance up there with us.
As such, I'm frequently interested in seeing how other bands will do it and I'm always looking for inspiration.
Which is when I came across this!
https://www.youtube.com/watch?v=Wz5GSeI41Ro
Watch carefully!
They bring a kid onstage. That's not unheard of. She looks like a nice normal kid and obviously has loving parents who care about her hearing. Those are pretty good muff-style hearing protectors!
They let the kid play the drum for a brief minute and then they whisk the kid off the stage - to the back of the stage.
As in, they bring the kid up on the front of the stage - and then shoo the kid off, never to be seen again, to the back of the stage! The kid just disappears!
Damn it, Metallica! You stole a child!
Yes. Yes, this is research!
Slight edit...
'Snot the "best thing." Now that I think about it, it's just "pretty good."
"Best" would be hyperbole and not correct!
There are much better - such as gigs in bars where the ladies sometimes show us their tits. We aren't even famous, and we get tits.
I'm pretty sure that's a good reason to get your kids involved in music!