Prior to Souls At Zero, Neurosis came primarily from a hardcore background. That much is still evident in the vocal delivery on the songs. That is basically the only evidence of their hardcore background, however, as the music otherwise explores much slower tempos, layering, and atmosphere. "Sterile Vision" has a simple acoustic guitar figure throughout most of the song accompanied by reverb-drenched drums and induces a slow headbang long before the distorted guitars kick in. "A Chronlogy For Survival," the longest song (at 9:33) on an album full of long tracks (5 of the original 10 tracks are over 7 minutes) is another one that hits the full spectrum between distortion and feedback at one end and clean guitars and a violin melody at the other end. The two bonus demo verisons are interesting, as is the more chaotic, drum-driven live "Cleanse III."