The Lollapalooza lineup includes:
* Primus: This Bay Area trio has been around since the late '80s, and cracked the Billboard Top 10 with its latest album, "Pork Soda." Driven by the thumb-thumping virtuosity of bassist Les Claypool, Primus' sound has been described as "funkcore" (though Claypool insists that the band's R&B; content is negligible), and much of its material relies on adventurous improvisation and Zappa-esque wit.
* Alice in Chains: Hailing from Seattle, this quartet's sound is more heavy than grungy, and the band seems especially given to catchy choruses and hypnotic, slow-churning riffs. With two albums and extensive touring to its credit, A.I.C. is perhaps the most seasoned live act on the bill.
* Dinosaur Jr.: The brainchild of guitarist-songwriter J. Mascis, Dino Jr. comes off like a classic indie guitar band in the studio, and an under-rehearsed jam session onstage. That's fine by those eager for more of Mascis' Neil Young-inspired guitar solos, but may disappoint fans more interested in songcraft.
* Fishbone: Eclectic and hyperkinetic, Fishbone's blend of hard rock, funk, gospel and ska produces more energy onstage than most nuclear reactors. And even though the band's latest album more metal-edged than its predecessors, that hasn't yet affected the band's legendary live show.
* Arrested Development: Where most of the other acts come on hard, this Grammy-winning rap act always manages to keep its sound laid-back and down-home. And at their best, the members of A.D. exude a sense of community that's even more appealing than the pop hooks in hits like "Everyday People" and "Tennessee."
* Front 242: The only foreign act on the bill, this Belgian quartet helped pioneer the edgy, electronic sound we now know as industrial dance music, and influenced both its Lollapalooza predecessors, Nine Inch Nails and Ministry. Unfortunately, the Front relies a little too heavily on pre-programmed and prerecorded electronics to be a totally satisfying concert act.
* Tool: Hailing from L.A., Tool boasts a tightly coiled, throbbingly percussive attack and pointedly political lyrics, a combination that affords them both the instrumental might of Helmet and the passionate intensity of the Clash.
* Rage Against the Machine: Young, hot and rhythmically intense, this quartet doesn't just blend hard rock and hip-hop, it fuses the two into a something altogether different. Singer-rapper Zack de la Rocha is clearly the band's visual focus, but it's guitarist Tom Morello -- who can scratch on a guitar the way a DJ scratches on a turntable -- who usually steals the show.