Octahedron certainly continues the Mars Volta's tendency toward ambiguous, vaguely ominous sounding album titles (Amputecture, The Bedlam in Goliath) but otherwise mixes things up a little bit for the melodramatic prog rockers. "I consider it to be our acoustic album," guitarist Omar Rodriguez-Lopez said of Octahedron (which also features Red Hot Chili Peppers guitarist John Frusciante) back in 2008. How can one shred wicked solos if it's any kind of "acoustic album"? Not only that, but the new album's running time is a brief (for the Mars Volta) 49 minutes. Eight Mars Volta tracks in 49 minutes? No, they're not covers of Ramones songs, either. So what does this mean for Octahedron? Probably just that the word "progressive" isn't a label that The Mars Volta takes lightly.