PALO ALTO -- They had just played their biggest and most challenging gig yet -- a seven-song rock medley in front of nearly 6,000 people at Stanford's Maples Pavilion -- but the members of WJM weren't celebrating. They were too busy breaking down the show.
"The transition between 'Don't Stop Believing' and 'Give Peace a Chance' didn't work," said Jeremy, the lead guitarist, his shoulder-length dark hair framed by a backward baseball cap.
William, the shaggy blond lead singer, hadn't been able to hear how his voice came across on the monitors. Not to worry, said Jeremy: "You sounded good, dude."
It was a normal backstage conversation among musicians -- except for the fact that William, Jeremy and bandmate Max are 11 years old.
Though they just completed the fifth grade, the members of WJM already come across like pros. And for the past 18 months they have charmed Bay Area audiences with a precocious blend of talent and charisma. On Saturday they took the next step in their musical development, playing a 30-minute set at an Idaho rock festival headlined by Queensryche.
The band's growing popularity presents unique obstacles and opportunities for their parents, who strive for a tricky balance: giving their children the space to pursue their passion while protecting them from burnout and overexposure. The parents donate proceeds from the shows to charities, while teaching the kids about the causes, and encourage them to write songs with socially aware lyrics.
"What we're hoping to do is raise good citizens," said Joon Yun, father of the guitarist. "It's enormously rewarding to have something they love be a vehicle for discovering the world."
William, Jeremy and Max, who plays drums, are by all appearances normal 11-year-olds -- goofy one minute and serious the next, easygoing yet beginning to express strong points of view. But they share an uncommon musical drive.
Jeremy taught himself to play guitar when he was 5 by watching YouTube videos. If he doesn't have perfect pitch, he's close. Hum a note or ring a doorbell, and he can tell you whether it's an A-flat or C-sharp.
"There's kids that are pushed into music that get upset when you ask them to practice," said his father. "He would cry when we asked him to stop."
At 9 months, William began repeating melodies his parents played for him. His mother, Johanna Jirven-Lipton, remembers him belting out nonsensical tunes as a toddler while playing with his Legos and trains.
Three-year-old Max was an incessant hand-drummer. By the age of 6, he was playing along to rock songs on a drum kit.
All three absorbed their parents' affinity for classic rock, but they gravitate toward the harder stuff. Their sets feature skilled covers of Led Zeppelin, AC/DC, Green Day and the Foo Fighters.
WJM formed after William and Jeremy met at the School of Rock in San Mateo in 2009. Max joined in 2012 when his father met Jeremy's dad at a business meeting.
Much of the band's growth has been fueled by social media and word-of-mouth -- there's something about seeing kids under 5 feet tall bang out "Paradise City" by Guns N' Roses that gets people talking.
Shana Hart, owner of the Rock the Falls festival, was vacationing last July when she caught them playing at Pier 39 in San Francisco. She was blown away by their stage presence.
"You just can't stop watching them," said Hart, who invited WJM to be the opening act on the main stage of the Idaho festival, which was expected to draw several thousand people or more. "They're like these little 10 year olds, but they act like they're 30."
The joy of rocking
Despite WJM's musical maturity, their parents are determined to let them be kids. They avoid overscheduling them and encourage them to try other things.
Jeremy, who lives on the Peninsula, plays baseball and golf. William does taekwondo. Max, who lives in the East Bay, draws and makes movies.
But no experience so far compares with rocking out in front of a crowd.
"I just like going nuts onstage and singing my heart out," said William, a considerate Peninsula child who is a blaze of energy behind a microphone. Jeremy is laid-back, but he turns into a showman when he plugs in his electric guitar.
Max's happy-go-lucky personality is magnified onstage. He grins ear to ear while smashing the drums, his blond hair flying. He wants to travel the world "playing ginormous stages" when he grows up.
"When they're on the stage, I don't think there's anything better in life," said the drummer's father, Paolo Simas. "It trumps the baseball, it trumps the karate, it trumps everything."
The Stanford performance came in March at half-time of the final regular season home game for the women's basketball team.
The afternoon soundcheck was plagued by technical problems, but as the boys waited by a tunnel that night for the first half to end, they seemed unaffected by the chaos.
William appeared to have his usual preperformance butterflies. Jeremy casually strummed his unplugged guitar. Max was loose as always.
There was an awkward pause once they reached center court, as if they were unsure how to start. Then William shouted "All aboard!" and the band launched into Ozzy Osbourne's metal classic "Crazy Train."
Max's 18-year-old brother, Collin, played bass that night. William is learning the instrument, but it restricts his movement onstage.
The band could eventually add a fourth member, but there are concerns about disrupting the group's chemistry -- not just among the kids, who are close friends, but among the parents, who have harmonious views on WJM's trajectory.
The parents deliberated carefully before letting their kids play Rock the Falls. Their goal is to let the band grow organically, not seek instant fame.
The future of WJM hinges partly on developing original songs -- and they've already made a few. How that works out, and the answers to many other questions, will increasingly be up to the kids.
"If they decided to pack it in and blend right back into their normal lives, that's great," said Yun. "But more and more it seems they are manifesting their own destinies."
Contact Aaron Kinney at 650-348-4357. Follow him at Twitter.com/kinneytimes.