A Rock Star in What Way?

When I picked Zeb up from daycare the other day, I saw Bette, the mom of a boy who went to school with Lulu.
His name was Mason and we remember him because he supposedly made up one of Lulu's favorite jokes: "Knock Knock. Who's there? Someone in your underwear.''
Mason was kind of a shy, though. He seemed to come from a happy home, but he often looked forlorn when I came to get Lulu at the end of he day.
Bette, on the other hand, was glamorous--a thin and funky stay-at-home mom in a Lexus SUV. She had curly blonde hair and an array of casually chic outfits that she could wear without a bra because she was so flatchested and fit.
She was nice, too, the kind of woman who would hug you with apparent sincerity if she hadn't seen you in awhile.
I hadn't seen her in awhile, so she hugged me.
She asked how Lulu was doing and I gave the perfunctory answer: good, she likes second-grade.
When I asked about Mason, Bette replied with a proud little sigh: "Oh, he's a rock star.''
I was annoyed and a little puzzled. It seemed like bragging. But what exactly did she mean by this? That he was no longer so shy? That he was singing or playing the guitar? That he had developed a flair for self-dramatazation?
I didn't know. And I didn't ask. I just said, "Oh, that's good. He likes second-grade?''
Driving home, though, I wished I would have said, "Oh, so is Lulu! She is a HUGE rock star.''
I love rock stars as much as the next person--in fact, far more than the next person--I am a thwarted groupie. So of course I think my own children are destined to be the biggest rock stars of all.
Lulu, I imagine, will front a punk band, sneering vivaciously as she prances around in a torn dress, a cross between Hole-era Courtney and Poly Styrene.
Zeb is a singer-songwriter kind of dude. He'll be the tall quiet bassist who is the creative force behind the obscure but influential indie rock outfit. (But he can also dance and play keyboards, so I can also see him as a hip-hop producer).
But what kind of rock star is Mason?
I guess his mother is the only one who knows.