The Mars Volta’s fifth studio album is a full 25 minutes shorter than their fourth, and doesn’t get around to a real guitar solo until about five minutes into "Luciforms," its second to last song. Even then, the requisite jazz-fusion freakout is cut to a tasteful (and awesome) three minutes. What gives, guys? Opener "Since We’ve Been Wrong" clocks in at a meaty seven-plus minutes, but it boasts an honest-to-god song structure with a chorus and verses and shit, carried by Cedric Bixler-Zavala’s voice, of all things, and it’s no less strikingly pretty for sounding like a neutered version of Led Zeppelin’s "No Quarter." Octahedron’s most Voltian track, "Cotopaxi" (needlessly hard to pronounce name and all), is mercifully also the album’s shortest, since it continues in the ill-advised chipmunk-voiced disco-funk of 2007’s Bedlam in Goliath. Otherwise there’s hardly an unnecessary note. Diehard fans may be disappointed, but Octahedron might be the first Volta album since Deloused in the Comatorium that anybody else will sit through.