Upon first listen, you'll be hard pressed to categorize Tool [ tickets ]'s new album, "10,000 Days." Is it packed with sidewinder epics, another of the band's long-awaited masterpieces, ala 1996's "Aenima"? Or, is it finally Tool's jump-the-shark moment, when the 16-year-old band gorges itself on 11-minute songs with names like "Rosetta Stoned"?

The answer: yes.

Tool has always been a band that pushed the limits of excess, from song structure and CD artwork, to videos and live performance. "10,000 Days," from its remarkable packaging to its sprawling music, is a feast. While the result is certainly an excessive album, it is decidedly, unapologetically, a Tool album.

Openers "Vicarious" and "Jambi" are engulfed in guitarist Adam Jones' familiar schizophrenic machine-gun fretwork. "Wings for Marie (Pt 1)" and "10,000 Days (Wings Pt 2)," tracks 3 and 4, respectively, present sixteen minutes of bulging metal beginning with one slow steady drop of sound.

Often, however, especially throughout the disc's second half, instrumental sections (and weird go-nowhere tracks) last too long, losing some of their potency along the way.

Like most Tool efforts, "10,000 Days" is dark, apocalyptic and dense. Its grandeur reveals Tool's limitless ambition, making it one of the group's most impressive, if unfocused, albums yet.