While Children of Bodom are used to personnel shakeups, the departure of longtime guitarist Roope Latvala before the recording of I Worship Chaos posed a challenge.

A member since 2003, he was an integral part of the band's sound.

This left vocalist/guitarist Alexi Laiho handling all six-string chores alone for the first time, making this COB's debut as a quartet.

It was recorded in a converted warehouse rather than a conventional recording studio, and delivers a more spacious sound.

Laiho and bassist Henkka Seppälä tuned half a step lower for each song, resulting in a much darker, heavier attack.

Opener "I Hurt" is classic COB with a knotty, technical death metal riff, labyrinthine scalar flights, and piercing melodic interludes.

The band's characteristic mastery of rhythmic syncopation is heard best on "My Bodom (I Am the Only One)," with drummer Jaska Raatikainen adding counterpoint as he alternates between martial cadences and blastbeats and the whole tune crisscrosses time signatures.

The new bottom-end string throb is most punishing on "Horns" and "Suicide Bomber," insanely tempoed, blackened thrashers heavier than anything COB has recorded in a decade.

Keyboardist Janne Wirman becomes more integral to the mix.

He adds force to the band's classic melo-tech death metal charge, and provides utterly seductive, sinister atmospherics in these new songs.

He can either create swirling chordal backdrops -- as on the crunchy, doom-tinged "Prayer for the Afflicted" -- or powerful, fleet, single-note exchanges with Laiho -- as on the glorious "Morrigan." The latter is a medium-tempo groover and a clear single.

Its riff is fueled by an infectious guitar hook as the drums alternate between pronounced swing and double-timed frenzy.

It contains a chanted chorus and spiraling crescendoes.

This passes for a stadium rock anthem.

"All for Nothing" is an outlier even in COB's loopy catalog.

It has an Iron Maiden-esque guitar and bass riff, with eloquent acoustic piano lines and transcendent melody atop thundering drums.

Laiho delivers a screaming extended solo followed by one from Wirman on synth as they trade lines to take it out.

The songwriting on I Worship Chaos is impressive, as if the quartet format forced COB to focus on delivering tunes of real substance before anything else.

The performances are equally inspired -- the material is so good, it challenge the musicians to pull it off.

This is the sound of a grown-up COB; it may not be as unhinged as their earliest records, but it's nearly as misanthropic.

This band still has very sharp teeth, a nasty disposition, and a dark, even malevolent sense of humor.