Led Zeppelin are "the forefathers of modern rock," Snelling said after the show. (According to her mother, Gigi has a Robert Plant poster on her bedroom wall.)
Her little brother Liam, 10, who plays guitar in the group, chimed in, "Jimmy Page is God."
MusicGarage's repertoire isn't all Led Zeppelin, though the set included Nirvana, Jimi Hendrix, Pink Floyd, Iron Maiden, and a spirited finale of Rush's "Tom Sawyer."
"The kids pick their own music I don't tell them what to play," said Steve Auerbach, director of MusicGarage.org.
Why do the kids pick music that predates them by a couple of decades? "They're musicians, so they pick the music that's challenging musically," Auerbach said. "Maybe they're raiding their parents' record collection."
Yes and no, said Gigi and Liam's father, Jeff Snelling.
Though the family plays lots of music at home, he said the children "have introduced us to a lot of things. I never liked Iron Maiden as a kid, and now I do."
Michele Snelling, Gigi and Liam's mom, said the MusicGarage experience has taught teamwork, as well as "confidence, and how to be in a band."
Gigi Snelling said she was nervous the first time she sang on stage. "I was kind of afraid to be a frontwoman at first," she said. "The more I practiced, the easier I became."
MusicGarage isn't the only group of young musicians playing the Park Stage today. It's become a Utah Arts Festival tradition to start the first day with young musicians. Teens from Soul Research Foundation played after MusicGarage, grooving on everything from Aretha to Adele.Sandy's School of Rock and Wasatch Music Academy were scheduled to follow.
Being on the Park Stage, where big-name acts will play later in the evening, is appropriate. "This is where it starts," Michele Snelling said. "These kids will become the bands that are headlining."