Metal purists are always going to have a problem when their favorite bands evolve, but Mastodon’s fourth album, Crack the Skye, poses an especially tough conundrum. Thanks to production from noted rock-radio maker Brendan O’Brien, the music on Skye is even slicker and more accessible than 2006’s Blood Mountain, which was itself a huge step forward from the thrash/speed metal harshness of 2002’s Leviathan. Sludgy tempos, towering stoner-lite riffs and minor-key dirges abound (think Pelican or Russian Circles), while vocalist Brent Hinds now sounds like Ozzy Osbourne with a head cold.
Of course, accessible is a relative term where Mastodon is concerned, and Skye’s arrangements are anything but pedestrian. Epic and absorbing closing track “The Last Baron” is a full 13 minutes of minor-key piano, fret acrobatics and vocal wind tunnels, while highlight “Quintessence” mashes together Motörhead-like moments of speed and towering ’90s rock. Better still is the drilling, progged-out title track, which features doomsday vocals from Scott Kelly of Neurosis and copper-plated layers of harmonies.
Such density doesn’t always work; “The Czar,” for instance, is 10 interminable minutes of meandering vocal angst and dolphin-wail guitars. And Skye often feels too ambitious for its own good, an album so complex that it takes multiple listens to parse. Even then, those who like their music dangerous will likely find Mastodon circa 2009 entirely too tame to abide.