Task: Question Answering
Input (English): Passage: With 2008's obZen, Meshuggah moved away from the experimentation of 2002's Nothing and 2005's Catch Thirtythree to return to the musical style of its previous albums, such as Contradictions Collapse, Destroy Erase Improve and Chaosphere, while still maintaining its focus on musical and technical innovation. The album loses some of the mathematical-like rhythmal quick changes of past releases and the melodic orchestration of Catch Thirty-Three and uses "angular" riffs, mid-tempo and common 4/4 beats. The album is a culmination of the band's previous work. Meshuggah decided to self-produce because it sought to retain artistic control over 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". 
Question: What is the name of the album that loses some of the mathematical-like rhythmical quick changes of past releases and uses "angular" riffs, mid-tempo and common 4/4 beats?
Output (English): obZen.