Pantera's breakthrough album, Cowboys from Hell, is largely driven by the band's powerful rhythm section and guitarist Diamond Darrell (as he was then known)'s unbelievably forceful riffing, which skittered around the downbeats to produce unexpected rhythmic phrases and accents, as well as his inventive soloing. Phil Anselmo displayed a vocal range that could switch from a growling shout to a high falsetto -- listen to him match Darrell's harmonic squeals at the end of "Cemetery Gates." The album gradually becomes more same-sounding as it goes on, but the first half, featuring such brutal slices of thrash as "Psycho Holiday," "Primal Concrete Sledge," and the title track, pretty much carries its momentum all the way through.