Noise as purgative: Tool shove their iron-spike riffing and shock-therapy polemics right up the claustrophobic dead end of so-called alternative metal in the name of a greater metaphysical glory — something along the fuzzy lines of Jungian cyberoccultism. That’s all very admirable and even a bit impressive; anyone who tries to elevate heavy music above cock-rock clown time is to be encouraged. Still, the best parts of Ænima come when Tool just let the music rip and dip with the broiling, avant-metal ferocity of Led Zeppelin’s Presence. Also, let us call a moratorium on concept CDs that come with lightweight “Intermission” instrumental tracks. If you need to take a piss in the middle of the record, just hit the pause button.