The first time my granddaughter Sloane played guitar in public was at a recital a few months after she began taking lessons at 7, grouped with nine other students to strum Taylor Swift and Bruno Mars songs.

It was suggested Sloane yield to older girls and sit out a few numbers with complex chords, but she was never one to stand down from a challenge.

She intently practiced the chords and played along at the recital without missing a beat.

I recalled that determination last week when I watched Sloane, now 11, blast power chords through the Blaisdell Arena as a member of the punk rock band Random Weirdos, which got the prized invitation to open for rock icon Jack White.

I worried five kids ages 11 to 13 would look tiny on such a big stage, but from the moment they strapped on their instruments, they looked — and played — like they belonged there.

Any nerves were gone with the first drum beat and they quickly got the audience moving to the pulsing sound of punk classics such as "Midnight Spookshow," "Give It All" and "Anarchy."

It was the confidence of youth — and hundreds of hours of practice.

Is their music to my taste? No, but you have to let kids find their own musical passion and I respected the years of hard work they had put into getting to the Blaisdell.

The Random Weirdos were organized in 2011 by the Kailua Music School’s Aaron Carey, who has guided them ever since.

Sloane was an original member along with the Miller brothers, bassist Tristan, now 13, and drummer Luke, 12.

Together, they’ve held the band together through various lineup changes; the group at the Blaisdell included guitarist/vocalist Storm Wilson, 12, and vocalist Aspen Rice, 13.

They grooved their sound with weekend practices and weekly performances in front of the Pali Lanes bowling alley for the Kailua Farmers Market crowd — even when tired from long school days.

As they improved, they graduated to Wednesday gigs at Boardriders Kailua and have played the 50th State Fair, the Haleiwa Arts Festival and clubs around Oahu.

Performer and teacher Erin Smith, busy with the release of her "American Boys" album, found time to coach the Weirdos on stage presence and it showed at the Blaisdell, as you can see in this clip of "Blitzkrieg Bop," with Sloane putting down her guitar to take lead vocals: 808ne.ws/1Jd5v3a.

When she was 8, Sloane eyed a pricey Gibson guitar at the music store and asked, "When are you going to buy me this one?"

"Not for playing the bowling alley," I said. "Talk to me when you play the Blaisdell."

Luckily, memories are short in kid years and she seldom reads my column.

Reach David Shapiro at volcanicash@gmail.com or blog.volcanicash.net.