Since the dawn of distortion, men have fronted metal bands for simple reasons, like sex, drugs and the joy of wrecking hotel rooms. David Lee Roth has partaken of his share of groupies, consumed his share of drugs and trashed a whole Holiday Inn's worth of suites. But throughout his career as lead singer of Van Halen, and now as a solo artist, he's had another ambition, one a bit more esoteric and a lot less sordid.

He's on a mission from God.

The God of Moses, to be specific. The God -- let's just spell this out here, shall we? -- of the Jews.

"There's not a lot of Jewish action figures," says Roth. "Heroes for little Jewish kids are very few and far between when it comes to belligerent enthusiasm, a confrontational red-meat approach. I'm a highly literate slut. I dig only intellectual smut."

Roth is sitting in his tour bus behind the 9:30 club, where he's just finished a swaggering two-hour concert filled with karate kicks, crotch grabs and Van Halen classics. He's just now getting his breath back, drinking a Budweiser and sporting lace-up leather pants and an unbuttoned, showbiz-blue shirt studded with tiny jewels. The mane of blond hair is more silvery now, but at 47, he's as lean as he was in the days when Van Halen was an MTV darling and you couldn't sweep the radio for 10 minutes without running into "Jump," or any of the band's other hits.

As he explained in his autobiography, "Crazy From the Heat," Roth relished every decadent minute of band life, but much of his style and energy came from fury over anti-Semitism and an urge to crush Jewish stereotypes. That might surprise longtime Van Halen fans who missed the Talmudic side of Roth's tequila-Tarzan persona. But as Roth explained on the bus Tuesday night, he's never stopped celebrating the idea of Jewish identity.

"Be different," he says. "Keep it separate. Every neighborhood's got something to contribute, so let's not mash it all together, let's not shop at Beige R Us. No, I want a bagel in the morning and Chinese food at lunch, and I'd like a Russian to teach me chess, and I want a Mexican to make me tacos. And there should be a black guy on bass."

Roth pauses for a cackle. He cackles a lot, raspily and for way longer than most people cackle. It turns his eyes into maniacal slits.

"Viva la difference, as they say in Israel," he says, lifting his Bud toward the ceiling and cackling again.

There's some madness in that laugh, and at various moments in this 15-minute interview, it's easier to figure out when the punch lines have arrived than the logical links between the setup and the joke.

"Like it says in the Bible, turn the other cheek, kid," he effuses at one point. "Welcome to Weber grill territory. Ha ha ha ha ha ha ha!"

What? It doesn't really matter, because Roth can sound oracular as often as loopy and he perpetually exudes a joy that says, The party already started, dude. His show these days is mostly Van Halen hits, including "Everybody Wants Some," "Panama," "Hot for Teacher" and "Dance the Night Away." Lead-guitar duties fall to the frizzy-haired Brian Young, whose qualifications include a stint in a Van Halen tribute band.

Onstage, Roth is a few parts Bruce Lee, a little bit of Neil Diamond and a whole lot of porn star. He kick-spins like a cornered martial artist, leaps occasionally off the drum riser and suggestively wedges his microphone down his pants. He keeps a bottle of Jack Daniel's nearby, which he sips in dramatic gestures designed to look like heavy swigs. Most of the booze actually ends up sprinkled on fans near the lip of the stage.

"You do more for brunettes than anyone since Snow White," Roth leers midway through the show, pointing at a woman a few rows back. She's invited to come forward, close her eyes and place her hand on Roth's fly, which she gamely does. Roth clasps her hand in place, grinds his hips a little and mentions "little Elvis." Later he grabs a Japanese fighting stick and spins it like the blade of a Cuisinart. The crowd, which includes both fortyish Van Halen stalwarts and 23-year-old classic rock fans, hoot throughout the evening like drunks at spring break.

"My whole show is based on something between the guy in Led Zeppelin and chief of the village at Club Med," Roth says later on the bus. "Somewhere between 'and she's buying a stairway to heaven . . .' and 'don't forget, two-for-one happy hour, 5 till February. Welcome to Diamond Dave's tiki bunker.' Ha ha ha ha ha ha! It's Spider-Man meets Groucho Marx. Ha ha ha ha ha ha!"

Roth appreciates the gaudiness of the show, its dated crudeness, its nostalgia for teased locks and tight trousers. It's a caricature now, of course, but it's not a Jewish caricature, which for him saves it from cliche. Maybe it's not a lesson that the graybeards in the faith want to teach in Hebrew school, but if his career proves anything it's that a bar mitzvah boy can do lewd and loud as well as anyone else.

"Jewish kids take a paperback to the beach instead of a football," he says, half-approvingly. Roth might take a paperback, but he'd persuade a dozen blondes in bikinis to join him and then shoot a raunchy music video when he wasn't reading. If he still had the spendthrift budget of his Van Halen days, he says he'd have a Portuguese teacher on another bus, a kung fu teacher on another bus and a chess tutor stashed somewhere else.

"I don't want to get off the bus the same guy who got on 10 weeks ago," he says, momentarily serious. "Let's take this somewhere. Let's take ourselves somewhere. Why would I do this again and again? To repeat? No. To improve. The same thing only better. Ha ha ha ha ha ha ha!"

And how long will Roth be on this bus?

"Until Hanukah," he says, laughing. "Eight encores, baby!"

Roth onstage: A few parts Bruce Lee, a little bit of Neil Diamond and a whole lot of porn star.David Lee Roth at the 9:30 club. "I don't want to get off the bus the same guy who got on 10 weeks ago," he says.