Prong's Tommy Victor recently remarked that metal bands can't play in standard E tuning anymore because they'd "sound like the Eagles." Not that Meshuggah ever had anything to worry about, but about midway through the band's career, the guitarists switched from using already-low seven-string guitars to an eight-string approach in the monstrously low keys the band still works with today. Strangely, though, you could argue that the revered Swedish death/math-metal institution sounded heavier before putting out the eight-string albums Nothing and Catch 33.
Thankfully, on obZen, the band continues in the repetitive, low-droning vein of those two albums but also recaptures much of the frenetic energy that made earlier releases such as Destroy Erase Improve so thrilling. As much as Meshuggah rewrote rules and forever changed the face of metal, the band appears to have settled into a comfortable groove. obZen bodes well for the band's future because of its high energy level. The album never plods; in fact it presents Meshuggah at its most hypnotically repetitive and engaging.