Ozzfest vets System of a Down will be touring with Slipknot this fall and, like the Iowa laddies, they've just released their sophomore CD, Toxicity. Armenian Americans from California, System are far stranger and more engaging than Slipknot. Oh, they're as fast as the Flash and as hard as the Hulk, but they have a sense of dynamics, tempering their heaviness with unexpected touches of acoustic folksiness and prog-rock flourishes. Sometimes they come on like Fugazi playing Rush, other times they tread close to Frank Zappa territory. ''Prison Song'' features peculiar, Devo-like vocals and politically charged declarations like ''Drug money is used to rig elections that train brutal corporate-sponsored dictators.'' Then, lest you think they're humorless blowhards, they serve up a song that seems to be about a pogo stick (''Bounce''). Their music is crammed full of oddball spoken interjections, hardcore hectoring, and incongruous sloganeering; they'll gnash at gnarly riffs, then drag in a string section. ''Ariels'' drifts into a pastoral-jazz vibe and winds up sounding like, I don't know, Vietnamese folk music? It all adds up to a bizarro type of metal that has a warped majesty and strength.
If Slipknot make you fear for the future of metal, System of a Down at least prove that not every band of headbangers is chasing its tail. Still, I'm left with one nagging question: If all these Ozzfest bands deify Ozzy Osbourne, how come none of them can come up with a song as good as ''Iron Man''?