Vol. 2 and being involved in Deacon's side group Kynfolk. Natti would be the final member to join the group and end its formation. CunninLynguists released the third studio album, A Piece of Strange, on January 24, 2006, via Caroline Records and Groove Attack Distribution. It features guest spots included Cee-Lo Green, Immortal Technique and Tonedeff, among others, and is entirely produced by Kno. The album marked a significant turning point in the group's musical career, with the members turning their lyrics and music into more passionate material, and minimizing their "silliness". Hype gave the album a five star review describing it as "the best album of the last 12 months". URB gave the album four stars, describing it as "a piece of beauty, a soulful and sweeping assemblage of cuts that ride a steady wave of infectious momentum", and The A.V. Club commented on Kno's "masterful, adventurous production". The release of A Piece of Strange also saw their profile rise and cultivating a bigger and dedicated fanbase, as they toured abroad multiple times in support of the release, appearing live alongside notable acts such as Kanye West, Pharrell Williams, and The Strokes. CunninLynguists released their fourth studio album, Dirty Acres, on November 27, 2007, through a joint venture between their own label APOS Music and Swedish-based label Bad Taste Records. Produced entirely by Kno, it features artists such as Devin the Dude, Phonte of Little Brother and Witchdoctor, and was described by CMJ New Music Monthly as "a defiant album that questions everything, even the assumed standards of hip hop". It was lauded by Michael Kabran of PopMatters as "easily one of the best hip-hop albums of 2007 and arguably one of the best albums of the past decade". CunninLynguists made their way across the United States, Europe and Canada in support of the album, headlining the Dirty Acres Tour in 3 parts over the course of 2008. 2009–2013: Oneirology and Strange Journey Volumes One and Two The group released two mixtapes in 2009, Strange Journey Volume One and Strange Journey Volume Two. On March 22, 2011, the group released the fifth studio album, Oneirology. HipHopDX said about the album: "This project combines creative sounds with inventive rhymes and stands as an example of how a great group can come together to craft a well-made album worthy of praise." Its concept revolves around Oneirology, the scientific study of dreams.