Tool bridged the gap between the heavier end of grunge and the art-metal fringe, staking out territory where fans of Smashing Pumpkins, King Crimson, and Metallica might all find something worth savoring. 

 Undertow spirals out from the hammering riffs of "Prison Sex" and "Sober" into progressively more complex terrain. Adam Jones' guitar playing discards traditional solos in favor of texture, the stranger the better. 

 With Aenima, the band's ambitions nearly get the best of them. The increasing density of their relentlessly downcast music, augmented by occasional electronic noises, begins to feel ponderous. 

 Salival packages a handful of live performances and two new songs with some of Tool's deeply disturbing cutting-edge videos, which serve as a nightmarish backdrop for its concerts.  

 Brains and brawn meld on Lateralus, one of the more accomplished hard-rock albums of its time. "Reflection" is an unfortunate holdover from the droning Aenima era, but otherwise Carey and bassist Justin Chancellor are deep in the rhythm. 

 10,000 Days found the band's twisting, turning grooves as dizzying as ever, though the album also worked in eerie atmospherics ("Lost Keys") as well as some uncharacteristically touching lyrics from Keenan.