Show-Stopper : Dweezil Follows in Dad’s Footsteps : Music: Young Zappa proves to be a dedicated musician whose playing is both complex and relentless.

SAN DIEGO —  On Jan. 18, in a ballroom at the Disneyland Hotel in Anaheim, Dweezil Zappa’s band was well into its debut performance as the opening act for the “world reunion” of the spoof-metal trio, Spinal Tap. Suddenly, the 21-year-old guitarist stopped playing, waved the band silent, and asked the stage-lighting technicians to stop the overhead floods from flashing.

Three of the band members--bassist Scott Thunes, drummer Josh Freese, and San Diego guitarist Mike Keneally--exchanged bemused looks. In his first public performance of his own music, Zappa had broken an unwritten rule governing concert decorum: Unless there’s a genuine emergency, keep playing and deal with problems between songs.

The audience, perhaps assuming that Dweezil was exhibiting a fractured sense of humor inherited from his father, Frank, reacted to what they thought was part of the act. When the lighting was stabilized, the band started the tune over and completed their set without further incident. But in a phone call Tuesday from his home in L.A., Zappa--who brings the band to the Belly Up Tavern tonight--acknowledged that the Anaheim show established a precedent of sorts.

“I had people coming up to me afterward saying, ‘Hey, dude, that was really funny how you stopped the show like that,”’ said Zappa in a comical accent reminiscent of Cheech Marin. “They didn’t realize that I’d never played under flashing lights before, and that I was really nervous trying to play all these intricate guitar parts in front of an audience.”

It happened again recently at Club Lingerie in L.A. when Keneally’s guitar went badly out of tune and Zappa halted the band’s performance. “People thought we’d staged it,” Zappa said. “Now, we’re probably going to have guys bringing their friends to our shows and saying, ‘Wait for the part where they stop, dude--it’s really cool.” ’

For the good-natured musician, such misconceptions are part of the price he pays both for a genetically acquired perfectionism and for doing things his own way. The eldest son of one of contemporary music’s most idiosyncratic composers and controversial figures is charting a solo course through the music industry that in some respects resembles the serpentine route taken by dear old dad. In other ways, however, it is uniquely Dweezil.

Compared to the stop-and-go pacing of the typical rock concert, for example, the young Zappa’s shows are virtually relentless onslaughts of diabolical guitar riffing chopped into complex time-signatures. Parts are so meticulously arranged that mistakes could conceivably result in a chain-reaction disaster that Zappa characterizes as “a train wreck.” He considers his anxious concentration a preventive measure.

When things go according to plan, though, tunes roll almost seamlessly into one another until the momentum becomes a metallic juggernaut of rock, pop, and jazz that allows little room for audience participation. That’s in large part intentional.

“I’m different from a lot of musicians, in the sense that I just like to play and go home,” Zappa said of the band’s fire- drill performances. “And because I don’t anticipate anyone actually clapping after my songs, I purposely run them together,” he added, laughing.

Like papa, Dweezil is a gifted guitarist for whom musical complexity is instinctive. “I can’t read music, but I have a spastic sense of rhythm, so these weird time-changes come naturally to me. I don’t even realize they’re weird until I play them for the band and they get all over me about it.”

Two of the musicians are especially suited to the challenge--Keneally and Thunes are recent alumni of Frank Zappa’s band. As technically demanding as their sets are, the musicians manage to squeeze some levity into the proceedings.

“Talent-wise, this band is terrifying,” Zappa said as a compliment, “but we try not to take ourselves too seriously. So while we’re all playing these really difficult parts, we tend to act like complete buffoons onstage.”

The vocalist in Dweezil’s group is his 16-year-old brother, Ahmet, who made his entrance at the Disneyland gig wearing a cow mask. In a recent performance at the Coach House in San Juan Capistrano, Ahmet danced on the club’s tables, which are arranged tantalizingly close to and and level with the stage. “But he was considerate,” asserted Dweezil. “He gave the people at each table a chance to move their drinks.”

Fun, however, pushes beyond the mostly spontaneous antics of the players. A core element of the Zappa band’s show is a selection they call “The Medley,” which consists of snippets of songs from the past played in dizzyingly rapid succession. What began as a 30-song lark thrown together for a ‘70s theme party at the band’s rehearsal space last fall soon took on a life of its own.

Today, “The Medley” numbers such disparate songs as the Village People’s “Macho Man,” Paul Anka’s “(You’re) Having My Baby,” Led Zeppelin’s “Stairway to Heaven,” and the theme from “Smokey and the Bandit” among its 100-plus song-quotes.

“We’ve all got short attention spans, and we figure we can’t entertain an audience unless we’re entertained, too,” explained Zappa. “Besides, I get bored at concerts where someone just plays all the songs from his latest album.”

By that standard, no one at tonight’s concert should be bored. Although his third solo album, “Confessions,” is being released this week, Zappa claimed that only a few of its songs will be included in the band’s show. It’s Zappa’s way of keeping concert and studio work separate, although his creative methodology is similar for each.

Zappa’s “songs” actually begin as instrumentals, to which he later adds vocals. “I did the album that way, too,” said Zappa. “When the band was finished recording all the instrumental tracks, I went in and recorded the vocals.” The songs on the 73-minute-long “Confessions” even run together, like the selections in the band’s shows.

Zappa claims that every major record label passed on releasing “Confessions.” This despite the fact that suddenly marketable Donny Osmond contributes lead vocals on a heavy-metal version of the Bee Gees’ disco anthem, “Stayin’ Alive.” The album ended up on dad’s Barking Pumpkin label.

“I was forced into doing this project independently,” said Zappa. “I financed it myself, wrote, arranged, and produced the music, did the artwork, and hand-wrote the liner notes.” And when it came time to do a video of the first single, “Gotta Get to You,” Zappa directed it.

“I shot the video at a cost of only $15,000, which is a fraction of what they normally cost,” said Zappa, who starred with sister Moon Unit Zappa in last year’s sitcom, “Normal Life,” to which he also wrote the soundtrack. “No major label would have allowed me to do all that stuff myself. On the other hand, by assuming all this responsibility, I find myself constantly scrounging for money to save my life!”

Self-sufficiency is something Zappa learned from a master. “In my future, I see me making a bunch of albums and owning all my own masters (studio tapes). It’s sort of a family tradition.”

The Dweezil Zappa Band performs tonight at the Belly Up Tavern in Solana Beach. Opening the show at 9:30 p.m. is the band Talk Back.