Professional ratings
Aggregate scores
Source	Rating
Metacritic	(66/100)
Review scores
Source	Rating
Allmusic
Drowned in Sound	(7/10)
Entertainment Weekly	B−
Paste	(8/10) (Dovey) (5/10) (DuBrowa)
Pitchfork Media	(6/10)
PopMatters	(6/10)
Rolling Stone
Slant Magazine
Spin	(7/10)
Sputnikmusic

Octahedron is the fifth full-length studio album by American progressive rock band The Mars Volta, released on June 23, 2009. The album was released by Warner Bros. Records in North America and Mercury Records worldwide. It is the last studio album to feature drummer Thomas Pridgen and guitarist John Frusciante, and the first not to feature contributions from keyboardist Isaiah "Ikey" Owens.

Regarding the release, vocalist Cedric Bixler-Zavala states that the band "wanted to make the opposite of all the records we've done. All along we've threatened people that we'd make a pop record, and now we have."

It debuted at number 112 on the Billboard 200 albums chart with sales of 29,980 in its first week of release.

Omar Rodríguez-López started working on Octahedron in 2007 at the same time as The Bedlam in Goliath, in his typical fashion of working on two or three projects simultaneously. Yet as Bedlam turned into a "nightmare of a record to make" Rodriguez was unable to sustain both projects and devoted his attention on Bedlam.

In October 2007, a 30-second clip of a new song was leaked onto the Internet, originally assumed to be from the upcoming The Bedlam in Goliath. Later, the song (unofficially named "Beneath the Eyelids" by the fans) was played live by the band at the New Year's Eve show in San Francisco at the end of the acoustic set, introduced by Cedric Bixler-Zavala as "the song that we worked on that hasn't come out yet". The song eventually ended up on Octahedron as "Since We've Been Wrong".

Rodriguez had discussed the band's next album (then untitled) as early as January 2008, the month that The Bedlam in Goliath was released, claiming "I consider it to be our acoustic album." Bixler-Zavala has also spoken of the album as "acoustic" and "mellow," yet stated: "We know how people can be so linear in their way of thinking, so when they hear the new album, they're going to say, 'This is not an acoustic album! There's electricity throughout it!' But it's our version. That's what our band does -- celebrate mutations. It's our version of what we consider an acoustic album."

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Wikipedia