All kids like to show off. Give him or her or it the chance to learn something the people he is going to be in front of would appreciate and turn the kid loose.

Do not demand that the kid participate. At the same time do not leave just cause the kid is bored. Kids get bored easily.

Make a contract with the kid. Give them the opportunity to just be quietly present. They can do quiet, non-disruptive things. This gives the kid the opportunity to see that they can tolerate things not directly interesting to them today. It's amazine how often a kid will decide to participate on his own if it seems to be his ideas.

At the same time, take the kid's needs into account. There is no rule that says you have to stay for the whole time. Respect works. It's part of turning an animal into a human.

Sing a lot. If what the kid hears is familiar, it increases the likelihood of participation. Often the kid will decide that something you have sung is something he would like to try out on his own in public. Encourage the tendency. The greater the irreverence factor, the more the kid will like it.

By the way, I agree that Ken Schatz has grown up quite well.