Reviewing a Mars Volta album is evidently a tough job, as looking back over some contemporaneous examples finds writers coming away with not just markedly different opinions, but wildly conflicting observations, too. Never is that more evident than on Octahedron, a fifth album simultaneously considered wild and mellow, arcane and reflective. One point agreed on, however, and correctly so, is that it’s relatively accessible for an album named after an eight- sided geometric shape, and the first on which the band noticeably exercised some restraint. It’s their version of restraint, though, so while ballad Copernicus is a slimmed down spectacle, it glides past the seven-minute mark. And while the lyrics are more familiar, they still evade.