On Amputechture, the prog gods step back from universe-building to focus on songs. Evidenced by the brass-blaring "Meccamputechture," The Mars Volta still trade in jittery rhythms, mercurial grooves, and freaky guitars—all the more with John Frusciante sitting in—and three tracks blow past the 10-minute mark. Nevertheless, Omar Rodríguez-López aims his elastic nonet at cranking out tightly gnarled, darkly rocking jams like "Viscera Eyes." Without hard transitions, Cedric Bixler-Zavala's falsetto becomes soulful, while his lyrics clarify into barbs spat at institutions using faith as a cudgel.