On 's fourth full-length effort, and their debut for , the Texas prog metal quintet up their musical ante considerably. Given the four years that elapsed between , have taken their root-hooky, heavy, and immediate sound and shifted its focus considerably. ' 15 tracks clock in at nearly 55 minutes, with only one cut -- ten-minute closer "The Greener Grass" -- being over five minutes in length. Their melodies have become much more complex, their vocals more extensively layered with lush harmonies, and their guitar volumes remain at 11 on the volume scale though 's keyboards are a more central part of their attack. For those who were fans of the hooky melodies on , this may provide a challenge upon first listen, but it ultimately gives way to immense satisfaction with just a modicum of patience. "Heavens to Murgatroyd" opens the set as a 44-second intro, with a church organ and a preacher incoherently ranting before sledgehammer guitars, thrumming basslines, and double-timed drum introduce the death metal riff at the beginning of "Whiskey & Ritalin," but these just as quickly give way to an intricate, harmonic lyric line driven by a keyboard and double-tracked vocals. While it never loses its power, the cut's numerous textures and dimensions create a labyrinthine path for the listener to follow; it is a blueprint for the album as a whole. "Musical Chairs," with its acoustic piano intro, is quickly displaced by a full band assault, albeit one led by lush insistent keyboards. The use of a hammered dulcimer and a banjo interspersed with bone-crushing guitars on "Amarillo Sleeps on My Pillow," with its bluesy, country vocal by -- whose ability to move between nearly sweet and tender vocals and spirited HM growls is startling -- is the most beguiling cut on the set. (For a more jarring example, check "Rikki Tikki Tavi.") "Coppertank Island" sounds almost like fueled by keys and drums instead of guitars, though the latter are certainly present. The two final numbers, "Three Foolproof Ways to Buy the Farm" and the aforementioned "The Greener Grass," close on a more nebulous, experimental note that doesn't quite seem to fit with the rest of the album's precision and calculation, but this is a small complaint. For all the musical adventure and the growth it reflects, is 's finest effort to date. ~ Thom Jurek