Diamond Dave sells it well as Van Halen pours out the power at MGM Grand

Seated in the row behind me at Sunday night’s Van Halen show at MGM Grand Garden Arena were a woman and a young girl I took, accurately, as a mother and daughter.

Mom smiled with anticipation at seeing Van Halen, or at least 75 percent of the original Van Halen, in concert. The kid, not so much.

I asked how old the young lady was. Thirteen, she said. Her mother said her daughter had been listening to old Van Halen albums, “research,” she called it, for two weeks.

“I was 16 when I saw my first Van Halen concert,” I said, remembering a 1982 concert at Cow Palace in San Francisco, a show that rattled the rafters of the old barn. “I want to know what you think of this.”

It soon became apparent the young gal liked it a lot less than her mom did. The kid remained in her seat, her face a mask of boredom, for two hours. There was no nostalgia for her, just the careening, caterwauling performance at hand.

Too bad, because to enjoy Van Halen onstage in 2012, you have to had loved them in 1982. And “1984,” as well.

The latest incarnation of Van Halen clambered onstage Sunday night before a sold-out crowd of about 13,700 in full musical roar, high on life and performing with ample energy for an audience that stood and bounced for most of the show. A leaden drumbeat from Alex Van Halen (who turned 59 this month) powered into a two-punch combination of “Unchained” and “Runnin’ With the Devil.”

Swiftly, and rightfully, attention turned to David Lee Roth, the band’s joyous, original frontman. Diamond Dave -- you can’t help but smile at the man who has maintained his childlike sense of humor about his rock star persona -- introduced the fiery “Hot for Teacher” by saying, “I am Professor Rock, and I will be your instructor for the rest of the concert!”

Roth was certainly primed to put on a show. He strutted out wearing a sequin-studded blue-leather jacket and matching shiny, reptilian pants. Pretty snug trousers there, Dave. But Roth has always been the master showman, and even when a superior vocalist and musician has fronted the band (and this is a none-too-oblique reference to Sammy Hagar), Roth is still the favorite of most Van Halen fans. He is to Van Halen fans what Sean Connery is to devotees of the James Bond series. Other greats have followed, but there is an unshakable bond with the first.

Physically, Roth is in great condition for a man of 56, performing a couple of high-leg kicks and sauntering rhythmically and gracefully around the stage. The giant LED screen constructed behind the band, the largest I’ve ever seen at MGM Grand Garden Arena, showed Roth’s moments of gymnastics in slow motion moments after he enacted them. The adventurous use of the video screen, which beamed mostly in black-and-white except for the multicolored treatment of Alex Van Halen’s drum solo, was one of the night’s highlights.

To the fans’ delight, the big video screen caught Roth’s sashaying and his leering, peering countenance all night.

But the concern with Diamond Dave is even as he is the band’s master ringleader, his vocals are just not there. He tries, yes. Maybe you’ve cracked a tee shot 50 yards out of bounds. That’s how it is with Roth, who swings from the heels, sometimes hitting the fairway, but often losing the Titleist. Watching him work the stage is a classic case of enjoying what’s great and accepting what is lacking. Such terrific studio songs as “I’ll Wait” and “Ice Cream Man,” for two randomly selected numbers, were sung mostly by the amped-up audience over Roth’s ragged vocals, and this went on for most of the night.

But the guy Roth continually referred to as “Shreddy Krueger,” Eddie Van Halen, was in vintage form. He seemed in good shape, not the alarmingly whippet-thin figure from the 2007 tour, or the creaky, erratic performer described by Hagar in his tell-all book about his days with the band. Wailin’ Van Halen can still make the guitar sound like any number of instruments, including a synthesizer and a violin, and his inventive toying with the volume knob during his five-minute solo late in the show was something I’d not seen.

But it is not easy to take this version of Van Halen, even with Roth back in place, as the real deal. Not when Michael Anthony is still capable of playing bass but having been banished from the Van Halen empire to perform with Hagar’s Chickenfoot outfit. In Anthony’s spot is 21-year-old Wolfie Van Halen, Eddie’s son. The younger Van Halen is an odd fit onstage with the graybeards around him, and he’s become quite a husky kid. Wolfie looks like he can rock the house, instrument or no, big enough to be the starting defensive tackle at Van Halen A&M.

How long Van Halen remains a touring band is unclear, too. The band has announced that it is cutting short this tour -- in support of their most recent album, “A Different Kind of Truth,” after their July 26 appearance in New Orleans, ditching more than 30 dates. Many of those dates were sold out, and every show in June (including the Friday show at Staples Center in L.A.) is either sold out or offering only VIP seating.

It’s something of a mystery, the “why” of it all. Some reports restate the obvious: The band members can’t stand each other, and their differences are to be irreconcilable by July 26. Another version, from Roth as told to the Kansas City Star, is the band will be road weary by July. "The band is getting along famously," he says, "better than we have in quite some time."

Maybe Van Halen will hug it out, rest up and return to Vegas someday. To close the night, the band played the inexplicably synth-driven hit “Jump” from “1984.” “You got to roll with the punches to get to what’s real!” Roth called out before waving an oversized checkered flag in a blizzard of confetti.

Those in our row wheeled to the aisle to get a head start on the crowd streaming from the arena, but on the way out, I turned to the little girl.

She was still hunched in her seat, holding her head in her hand, as if about to yawn. You should have seen them in their prime, kid. That’s all I can say.

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