Tool's greatest breakthrough was to introduce dark, vaguely underground metal to the preening pretentiousness of art rock. Or maybe it was introducing the self-absorbed pretension of art rock to the wearing grind of post-thrash metal -- the order really doesn't matter. Though Metallica wrote their multi-sectioned, layered songs as if they were composers, they kept their musical attack ferociously at street level. Tool didn't. They embraced the artsy, faux-bohemian preoccupations of Jane's Addiction while they simultaneously paid musical homage to the dark, relentlessly bleak visions of grindcore, death metal, and thrash. Even with their post-punk influences, they executed their music with the ponderous, anti-song aesthetic of prog rock, alternating between long, detailed instrumental interludes and tuneless, pseudo-meaningful lyrical rants in their songs.
Tool, however, had a knack for conveying the strangled, oppressive angst that the alternative nation of the early '90s claimed as its own. So, the band was able to slip into the definition of alternative rock during the post-Nirvana era, landing a slot on the third Lollapalooza tour in 1993, which helped their first full-length debut album, Undertow, rocket into platinum status. By the time the band delivered their belated follow-up,