It felt like rock-and-roll Romper Room at Nation on Tuesday. The MTV-friendly pop-punk band Simple Plan brought out the rugrats in droves -- with their parents, of course. A little girl who looked like Cindy Lou Who held onto her mom with one hand and used the other to throw out devil horns -- while wearing a pair of jeans that said "Angel" in sequins. Meanwhile, a little boy in an oversize Simple Plan hoodie sat on his dad's shoulders and screamed whenever nasally lead singer Pierre Bouvier asked the crowd to "Make some noise!" -- which felt like every other song.

There were teenagers and adults at the concert, too, but considering the overall youthfulness of Simple Plan's audience, it was surprising to hear the band resort so often to a particular four-letter word and to see Bouvier do plenty of pelvic thrusts accompanied by a strategically placed microphone. While this Montreal quintet of early twenty-somethings probably never imagined that a large portion of its fans would be people who haven't had sex ed yet, it's pretty much the only audience that can hang with Bouvier's juvenile lyrics. The song titles are giveaways -- "I'm Just a Kid," "God Must Hate Me," "The Worst Day Ever" -- and even the titles that don't spell things out -- "Addicted," "I'd Do Anything," "Untitled" -- feature conversational lyrics that do.

What Simple Plan does have going for it is a great way with pop-punk melodies and gigantic guitar hooks. Every one of the 19 tight songs the band played sounded like a hit -- and a good many of them have been, including the show-closing ballad "Perfect." The group's playful concerts are super-energetic and include an abundance of audience interaction, synchronized jumping, water-bottle splashing, guitar-pick throwing and other general rock-and-roll dumbness. The li'l squirts ate it up.

-- Christopher Porter