by Eduardo Rivadavia   The sound of extremity defined, Salt Lake City's Gaza performs an unpredictable mixture of metal, sludge, and grindcore, which could very well be termed "progressive" due to its highly technical and innately unconventional approach. Introduced to mere mortals via 2006's bludgeoning and audacious Metal Blade debut I Don't Care Where I Go When I Die, the music's sense of dark mystery is further enhanced by players who prefer to keep their names and instruments anonymous.