Meshuggah made their mighty reputation on polyrhythm; if you know anything about them, you know they like to superimpose one time signature on another. Their dexterity has graduated to a new level: Now the band produces almost no pleasure at all. Their sixth full-length album is an exercise in loud, complex and clinical riff-writing; the drums, bubbling away in fast and detailed patterns, are so intrusive that it’s perilously close to drum-clinic music.

Around the time of Chaosphere, in 1998, Meshuggah had a bigger guitar sound and songs with a complicated groove, a kind of infinitely subdivided swing. Jens Kidman, the singer, had a little funk in his step, too: He made words bounce and syncopate.

With obZen, you’re left with technical concerns. You may want to count the beats per measure and notice the shifting patterns. You may wonder how they juggle so many rhythms at once, especially drummer Tomas Haake. But the stiff, weirdly disengaged, single-note guitar solos and Kidman’s monochromatic death screams don’t make you want to keep dragging yourself through the record.

This is specialist’s metal, with its own ideals of extreme technique and consistency. There’s no point in looking for hooks or humor or variety. The words are boilerplate omni-loathing: “Salvation found in vomit and blood/Where depravation, lies, corruption/War and pain is God.” Meshuggah achieve rhythmic virtuosity at the sake of everything else—what passes for melody, what passes for singing, what passes for lyrics or guitar soloing.

Live, they’re still a band to be savored. When the guitarists and bassist interlock, the riffs pan back and forth across your ears. But here, the band’s shortcomings seem suddenly pronounced, like a cartoon bodybuilder: neck like a paint can, biceps like watermelons, legs like matchsticks.

Download: “Combustion”