It's a good barometer of Sepultura's steadily muddled career prospects that the once hallowed Brazilian metal band's new albums are typically met with less curiosity and excitement than trepidation and outright dread, even by their most understanding and loyal fans. Already discredited by the loss of both Cavaleras (now reunited part-time in the Cavalera Conspiracy), whose family name, most observers would agree, still feels fundamentally inseparable from the Sepultura brand, the remaining lineup of their two replacements, vocalist Derrick Greene and drummer Jean Dolabella, plus founding bassist Paulo Jr. and longtime lead guitarist Andreas Kisser, has also been creatively wayward for several years now. None of which would have been a problem had 2006's Divine Comedy-inspired Dante XXI or 2009's A Clockwork Orange-based A-Lex backed up their highbrow literary aspirations with equally inventive music, but their general mediocrity only stoked the fires of fan discontent and these won't likely be extinguished by 2011's notably heavier Kairos. Never mind this album's own overly self-involved concept -- based on the ancient Greek term applied to crucial moments in time that affect unfolding events -- because what history, in all of its remorselessly selective judgment, will ultimately recall of Sepultura's twelfth studio album may be its game but mostly futile attempt at recovering the raw, thrash-based musical aggression of the band's middle years. Let's be clear now: technically speaking, this goal was achieved, but it's basically a hollow victory since there are still no songs worth mentioning in the same breath as glories past here, unless one rates them based solely on the fact that many -- "Relentless", "Seethe," certainly "Born Strong" -- could very well pass for Roots outtakes. But, beyond that, Sepultura mostly musters a seemingly endless parade of average, deliberate groove vehicles ("Spectrum," "Mask," "Dialog," which sounds like a sleepy Prong), a forgettable thrashing outbreak in "No One Will Stand," and a faithful cover of Ministry's "Just One Fix." Another semi-industrial, partly tribal mash-up called "Structure Violence (Azzes)" crosses the line of Roots parody one too many times, and a closing reworking of the Prodigy's "Firestarter," mysteriously renamed "4648," just adds to the confusion. Ironically, Kisser's guitar solos might constitute the album's best, consistent highlights, but that's no way to carry the day, nor attempt to maintain a legacy as important as Sepultura's still is, in spite of the many controversies and gradual musical dilution that followed Max Cavalera's exit in 1997. Again, it hasn't been for lack of trying on the revised band's part, nor patience or goodwill on the part of their fans -- just a lack of great songs -- and this is why Kairos invariably disappoints, and why only one outcome can truly restore the band's reputation, whether the four stubborn individuals involved can yet admit to it. Until then, Sepultura albums are bound to feel like speed-bumps in the road to salvation.