I was listening to Pure Holocaust recently, and I was struck by something I'd never fully appreciated. The drums on this one are bad ass in the best sense of the phrase. Immortal's other classic releases - like most of the better black metal from Bathory on down - used relatively simple, unwavering beats to create an ambient effect. On Pure Holocaust, percussion remains ambient in that songs tend to have long passages where the perceived pulse rate remains unchanged, but this is achieved by layering a variety of rhythms and drum textures at once, giving the ambient space vertical 'depth' as well as 'horizontal' uniformity. Add in that wonderful engineering that renders the tom sound particularly...cavernous, and you have an almost magically immersive tool. Pure genius. Listening to this really drives home the artlessness that most metal bands apply to drumming.