the recording and mixing process. For obZen, Haake returned to the drum kit most notably with his performance on the song "Bleed". In an interview for Gravemusic.com, Haake stated, "['Bleed'] was a big effort for me to learn, I had to find a totally new approach to playing the double bass drums to be able to do that stuff. I had never really done anything like that before like the fast bursts that go all the way through the song basically. So I actually spent as much time practicing that track alone as I did with all of the other tracks combined. It's kind of a big feat to change your approach like that and I'm glad we were able to nail it for the album. For a while though we didn't even know if it was going to make it to the album." Hagström also stated, "obZen is one of the most highly technical offerings the band has ever put to tape". Revolver Magazine confirms this statement: "At first listen, obZen seems less challenging to the listener than some of the band's other records, and most of the songs flow smoothly from one syncopated passage to the next. However, careful examination reveals that the material is some of the group's most complicated". A common quality in Koloss identified by multiple critics and outlets is the album's relatively straightforward, more groove-oriented sound, summed up by Metal Sucks as the band having "streamlined their compositions to a great extent." The broad style of the record has been described as "primal" and featuring "less jazzy virtuosity" than the band's previous output. Pitchfork noted that the record's rawer production style advanced this "tribal" sound further. The album invokes a greater sound of menace and "darkness" according to Metal Injection; additionally, Jens Kidman's vocals were described as "exponentially more anguished" than previous works. Metal Injection further compared the sound of the album's closing track "The Last Vigil" to works by the instrumental band Godspeed You! Black Emperor. The record's guitar riffs have been noted as deviating somewhat from Meshuggah's earlier catalog, with SPIN identifying "an almost bluesy swing" in the playing style. SPIN further elaborated on the guitar leads, comparing the solos in "The Demon's Name is Surveillance" and "Marrow" to the (non-metal) works of experimental composer Philip Glass and jazz-guitarist Allan Holdsworth respectively. The Violent Sleep of Reason For their eighth album, the