Mudvayne are often said to be the "new" Slipknot. Slipknot wear masks and are very famous; Mudvayne wear makeup and are getting there. And they both fit snugly into the new-fangled rock genre known as nu-metal. What's nu-metal? It's old metal but louder, faster and much more pretentious: It makes the all-conquering Limp Bizkit sound like your grandmother choking on a pistachio.

Ryknow pounding it out at Shibuya's Club Quattro

The first time I saw Mudvayne was on the sleeve of the debut album, "L.D. 50," which the record label sent me prior to the band's first gig in Japan at Shibuya's Club Quattro last week.

Gurrg (guitars) has a red face covered in big black spots like he's suffering from a particularly ugly strain of Ebola. Spag (drums) looks like the result of a unethical genetic experiment to cross a zebra and a human. Kud (vocals) looks like a cyborg version of Jack Nicholson's Joker, silver-headed with a big black devilish grin painted from cheek to cheek. And then there's Ryknow (bass), who looks like he's washed his face with joke-shop black soap that doesn't come off (doh!) and sports two red tufts of hair spiked to resemble devil horns.

The day after the show Ryknow will tell us that the band is from the planet Zeta Reticuli and are here preparing for the colonization of Earth by aliens wearing Black Sabbath T-shirts and studded wrist-bands or something like that, but we don't believe him, because we heard a rumor that Mudvayne is actually from a nondescript small town in Illinois.

Kud of Mudvayne; giving true entertainment.

"L.D. 50" is a riot of churning guitars, crunching bass-lines, depth-charge drumming and Kud trying to sing like a cross between Kurt Cobain and Thom Yorke during the slow bits and screeching demonically during the fast bits. In other words, it sounds a little like Slipknot, so we go to the gig.

"I want to see you going f**king loco . . . light this motherf**ker up!" instructs a silvery black-daubed Kud, who sports an impressive 1-meter long purple goatee.

Though he looks like a drag queen who's spent a month down a South Wales coal pit, wearing oversize dungarees that look like they've been passed down to him from Musashimaru, the kids obey and mosh like mad to "Internal Primates."

One song later and Kud's at it again: "I want to hear you make some goddamn noise. Let me f**king hear you!" The kids promptly scream along to "Prod."

The mosh pit is already a lively mass of writhing bodies and a never-ending supply of crowd-surfers are spewed out at the front, so Kud's urgings are pretty redundant.

At least Kud is grateful and he indulges in some corny feel-good fan worship: "You're the most important people here. It's not us, it's you. Give it up for yourselves." And then he urges everyone to buy a Mudvayne T-shirt.

He's dead right. Tonight it's the devoted fans, rather than a devoted band, that makes the night.

Kud's pedestrian frontmanship and Gurrg's compulsion to stand still, riffing away, means it's left to Ryknow to steal the show by displaying the onstage energy that Mudvayne's noise demands. The bassist puffs his cheeks like a frog, pokes his tongue out and wiggles it about like he's going down on a poltergeist and generally struts around with the mechanical motions of a Ray Harryhausen satyr.

At best, Mudvayne sounds like Nirvana unplugged until someone flicks a switch and the music blows the roof off, scorches the clouds and showers us in brimstone. But for the most part, Mudvayne seems subdued, which is a bummer considering the raw power of "L.D. 50," which can sit proudly next to your Slipknot.

After the gig I bump into the Chain-Whipped magazine crew. They invite me to crash their interview the next day on the condition we all paint our faces and take along a fish to get one of Mudvayne to bite its head off.

Next day, nursing a hangover, I find they are still deadly serious.

So armed with a fish in a bag full of ice and our faces painted in lurid colors we enter the Epic-Sony building and are cheered by all the staffers before being ushered into a back room.

Gurrg and Ryknow enter, take one look at us and . . . "What's all this about?" asks Ryknow, nonplussed, and suddenly the fish seems a bad idea, especially as it soon becomes apparent these guys take themselves very seriously.

Ryknow starts off with a joke (the aforementioned colonization plan), then explains they are an art project rather than just a band, talks about parallel universes, intuition through magic mushrooms and obscure artsy literature. He says he thought last night's show was great despite our misgivings and rabbits on about how, unlike nasty Americans, the Japanese are a nice, friendly and humble bunch of people.

I agree, but mention that Japanese tend to bottle up their anger until they get so demented that, rather than just kill the guy who's pissed them off, they decapitate him, stab his entire family to death and then eat his pets. I also drop in the black trucks spewing racism, sarin on the subway and the difficulty of getting a decent apartment if your skin's the wrong color.

"Those kind of things are very bad," acknowledges Ryknow, but we forgive his ignorance. The politeness of the natives easily confuses visitors, especially if they're from another planet like Illinois.

When I ask why the members of Mudvayne paint their faces, they eye me suspiciously. Then I remember my own face is bright blue.

Gurrg growls: "We want a more visual aspect. We want the shows to be theatrical."

"The makeup does not mean anything specific," Ryknow adds. "It started as fun but in time it brought us together as Mudvyane. If the fans keep supporting us the budget will get bigger and the shows will be more of a spectacle."

Mudvayne has also been accused of jumping on the Slipknot bandwagon.

"We do not have a problem with the association with Slipknot," Ryknow says. "They took us on tour with them. [Slipknot's] Clown is an executive producer on the album. Slipknot would not support a band if they thought the band was trying to rip them off. When we started we didn't even know about them."

So, is the band here to prime the kids for an appearance at Fuji Rock this summer? "It's something that we've been talking about," Gurrg admits. "But we are booked pretty solid until September with only two weeks off," adds Ryknow.

Don't hold your breath, but it seems likely Mudvayne, after this corporate hogfest of publicity, is gonna be back sooner than they think.