When heavy metal titans Mastodon agreed to deliver the music for the soundtrack of a surreal, special effects-laden Western named Jonah Hex, little did they know that their virtually unpaid volunteer work would require nearly a year of their time and the creation of two separate scores. The first, recorded in late 2009, comprised nearly an hour's worth of what the band deemed "pretty heavy" music, but which was eventually deemed unusable when the movie underwent significant re-shoots and re-editing, forcing Mastodon to start from scratch, resulting in a somewhat more restrained set of songs, finally released digitally in the summer of 2010 as the Jonah Hex: Revenge Gets Ugly EP. Indeed, the opening nine-minute "Death March" is one, long atmospheric crescendo built upon an ominous circular melody that never quite achieves its climax, unless it's in the shape of ensuing tune "Clayton Boys," which in turn contrasts menacing guitar strums splayed against dramatic synthesizer backdrops on its way to a brief, metal-thashing mad finale. This glimpse of Mastodon's best-known identity paves the way for a wholesale riffing bonanza called "Indian Theme," and then, following another ethereal and textural introduction, for one of the group's familiarly intricate semi-progressive workouts on the EP's final number, "Train Assault." If the Jonah Hex EP were to end here, one would come away satisfied but hardly wowed by Mastodon's virgin voyage into the -- ahem! -- wild, wild world of soundtrack music; but a simple pair of alternate versions tacked onto the end winds up making a world of difference. The second stab at "Death March," in particular, totally obliterates the original, thanks to incremental sonic layers and a sublimely sinister seam of guitar shredding strung throughout, but the similarly spruced up "Clayton Boys" isn't far behind, and, together, these relative afterthoughts transform Jonah Hex from a borderline wasted opportunity into essential listening for any self-respecting Mastodon fan.
AllMusic Review by Eduardo Rivadavia