Gnawing your way through a new Mars Volta record is always something of a chore at first. The band -- anchored by instrumentalist/composer Omar Rodriguez-Lopez and lyricist/vocalist Cedric Bixler-Zavala -- turns out huge mind-fucks as songs, mixing prog-metal, psychedelia and swaggering Latin flavors into massive, album-long narratives whose intent is to confound. Suffice it to say, Amputechture falls in line with those expectations -- only it's even more technically acute than past efforts, with sprawling tracks such as the album's standout, the nearly seventeen-minute "Tetragrammaton," and as much ear-twisting psychedelic rock as you can take in a single sitting. The disc marks a serious turning point for the outfit, in that it's the first record without a single narrative running through it (this time out, Bixler-Zavala has claimed inspiration from such disparate sources as the pro-immigration marches and news pieces about possessed nuns). As with previous releases, though, the reward comes after you've digested the concept and can focus on the ephemera. Pulsing with anxiety, frustration, yearning and, yes, the burden of over-intelligence, Amputechture succeeds in making you feel alive.