Generally speaking, the bands who shred the second stage at Ozzfest, and now the Rockstar Energy Mayhem, might as well bow down and worship at the feet of Slayer.

Taking its cue from the darkness of Black Sabbath and the hardcore thrash of Black Flag and the Misfits, Slayer took metal to the next level in the '80s with genre-defining albums like "Reign in Blood" and "South of Heaven." Satanic imagery, machine-gun guitars and Dave Lombardo's brutally fast drumming got the mall kids wearing Slayer shirts and groups like the Parents Music Resource Center (PMRC) to freak out about it.

Twenty-five years later, there's an industry of bands that feed off of what Slayer, Megadeth and Metallica wrought. Lombardo, for one, isn't all that wild about the disciples.

"I've been listening ... I've been trying to listen to these new and upcoming bands," Lombardo says. "I don't want to pass judgment on any one of them. My pet peeve with these bands is the fact that they record these records that they can't deliver live. They're so processed by computers. When I listen to a band, I listen to the drummer. They process and lose what the drummer is supposed to do. It just becomes a typewriter and there's no feel, there's no soul in the drummer. When you lose that, it becomes very bland. Yeah, you have all these breakdowns, all these tight jigajit-jigajit until they juice that and there's nothing left. It's very disappointing."

And on top of that is the Cookie Monster vocal, of which he doesn't count himself a fan.

"Yeah. Monster-sounding vocals mixed in with all that sweet vocal melody [b.s.]. It's like, 'C'mon man.' You know who did that well, though? Slipknot. It was natural for Corey Taylor to jump from the melodic voice into the screaming voice, but bands these days? Huh. Very disappointing."

As for how they react to Slayer, Lombardo says, "Yeah, of course, they've heard of Slayer, but I think what they've done is, they've not looked at the roots. In other words, they learned how to walk before they learned how to crawl. These bands, sometime, they go straight for the sprint marathon and lose what this music is, what they need to put into it to make it breathe. You need to create life into the music."

Lombardo adds that "amidst all these bands that wash up on the shore, there will be one or two that stick out."

On this tour, he says, of the young ones, he really likes watching the Welsh band Bullet for My Valentine, although it will be substituted at the Post-Gazette Pavilion for Mushroomhead.

The co-headliner with Slayer is Marilyn Manson, who always brings an eyeful and earful of grotesque goth-industrial metal. Manson recently told Spin "I like to believe that Slayer brings as much Satan on the road as we do. ... I think the anecdote to sum it up is that I haven't met anyone except Hunter S. Thompson and the guys in Slayer that can keep up with me when it comes to my intake of destructive forces."

Asked about that comment, Lombardo says, "It's not Manson, more like everyone else on the crew. He's the musician. It's everyone else going crazy and doing the debauchery. It's all good fun. Only as insane as you let it get. I mean, Bullet for My Valentine, they're nuts. Like good crazy. There are parties on their bus every night. If you ever need to find me, that's where I am."

When he's on the stage, Lombardo, a Havana native who joined Slayer in 1981 after delivering a pizza to guitarist Kerry King's house, is driving the band through a set of Slayer classics, while also teasing "World Painted Blood," which is on the way in September. Lombardo compares it to classic Slayer like "Reign in Blood," "South of Heaven" and "Seasons in the Abyss."

"I can't impose that opinion on anyone else in the band, but as the drummer, I feel it has what made those albums special."

The lead track is "Psychopathy Red," an account of Russian serial killer and cannibal Andrei Chikatilo in the grand Slayer tradition of gruesome, controversial songs like "Angel of Death."

Lombardo doesn't have any input into what Kerry King and Jeff Hanneman are writing, but he's never had a problem with it.

"It's all an art form," he says. "I don't have any problems with Stephen King or any horror movie writers or artists who depict horror or pain. If anybody has a problem, they're pretty narrow-minded to look upon music as the single source of problems in this world. It's the people who are born cracked. I mean, I play the music, I listened to the music. I'm not going out and killing anybody or trashing buildings or whatever. It has nothing to with the music."

There was a time when the PMRC was all over Slayer's back, but not so much anymore.

"No, because they realize how dumb they are," he says. "Time has showed them that, hey, we're not going anywhere. You're not going to shut us up. You want a little sticker on our record? Fine, put a little sticker on our record, but it's not going to change anything."

Lombardo thinks it's going to be a while before Slayer shuts up. As a drummer, he doesn't think he's slowed down at all, something that would certainly sink the band.

"Even at 43, I'm still a primed, well-oiled machine," he says. "I've seen bands where it's like 'God, please shoot me if I ever look or play like that.' With Slayer, we're still as brutal as we were as kids. They could roll up in their wheelchairs and play guitars, just as long as I'm beating the [crap] out of the drums, it's all good."