If there's one band that truly embodies anti-commercialism, it's Emperor.

Generally regarded as the one true master of the Norwegian-bred black metal art form, the band concocts a staggeringly violent whirlwind of carefully constructed noise resulting in nigh-impermeable records piled high with complex arrangements and heart-bursting violence.

So it's no surprise that, for its swan song, the band would issue Prometheus, a birth-to-death concept album of such weight and density that it takes roughly two dozen listens to even begin to appreciate the depth of its composition and its painstaking attention to detail.

Accompanying the release of Prometheus was the announcement that it would be Emperor's final word as a band, and listening to the record, it is increasingly apparent that the bandmembers were beginning to take divergent musical paths; drummer Trym and guitarist Samoth had started expressing more interest in gut-level power punches, while frontman Ihsahn wished to pursue more cerebral art, evident in his classical project Thou Shalt Suffer, and the strange, progressive output of side band Peccatum.

With Trym and Samoth investing the majority of their time in their relatively straightforward, speed-obsessed black/death unit Zyklon, Ihsahn willfully conceived, wrote, and produced the psychologically rigorous record in its entirety, handling all vocals, bass, keyboards, programming, and the majority of guitar tracks himself.

Earlier albums were certainly more collaborative, although Ihsahn's influence was always prevalent in Emperor's work.

Previous release IX Equilibrium was more immediate and simply arranged, albeit still putting forth the brainy, symphonic battery of much-praised earlier records In the Nightside Eclipse and Anthems to the Welkin at Dusk -- but Prometheus is an altogether different beast that still manages to stay true to the Emperor canon, boasting the group's best production to date with a mix that emphasizes clarity by pushing guitars to the forefront, more carefully integrating the keyboards, and bolstering the flat drum sound that marred previous recordings.

In addition, Ihsahn more cogently utilizes his variety of vocalizations, from mid-rangey black-throated screams to King Diamond-esque operatic singing to a deep, echoed spoken tone, all tying tightly into the lyrical story line.

Meanwhile, a tangled maelstrom of instrumental madness swirls behind him, the occasional melody or riff leaping out of the storm like a viper striking out from thick brush -- a device that Emperor easily mastered during their career.

Middle three tracks "The Prophet," "The Tongue of Fire," and "In the Wordless Chamber" are the album's most prominent manifestos, balancing memorable hooks with molten-hot, broiling ebullience, especially the latter track, which sports a Viking-horn call that rallies the chainmailed troops for battle.

"The Eruption" is an apt opening cut, kicking in with a delicately ominous harpsichord intro before bursting with effervescent rage, and "Thorns on My Grave" is a fittingly cold, harsh, and chaotic finale to both Prometheus and Emperor's legacy.

Those willing to invest a significant amount of time into Prometheus will be thoroughly rewarded on intellectual and emotional levels -- especially when drawing parallels between the album's elaborate concept and Emperor's musical reign -- while more practical listeners unwilling to slap on headphones and willfully ingest the lyrics will find the record impenetrable.

Certainly, In the Nightside Eclipse and Anthems to the Welkin at Dusk will still stand as two of the genre's defining moments, both albums redefining the creative boundaries of black metal in the mid-'90s, but Prometheus should proudly stand beside them, full of sound and fury, signifying a whole hell of a lot: Emperor, being all it can be, plunging the sword into its own breast after winning its most important battle (and possibly the war), willfully doing so before the plague of weakness has a chance to infiltrate its body.

No act could be more anti-commercial.