If Sound Hiearchy leaves you feeling like you've just consumed ten cups of extra-strong coffee, it's because of the element of density. While Roscoe Mitchell and his many admirers in the AACM have made extensive use of space when exploring "the outside" (an approach that is equally interesting, but not as jolting), this outstanding CD is just the opposite. The Sao Paulo native thrives on density, and he uses it to such an extent on Sound Hiearchy that the listener doesn't get a chance to catch his/her breath. Perelman is joined by pianist Marilyn Crispell, bassist William Parker and drummer Gerry Hemingway, and the quartet spares no passion whatsoever as it rips into such atonal pieces as "Frozen Tears," "Datchki Dandara" and "Fragments." Short of Charles Gayle, you won't find any 1990s avant-garde jazz that is more incendiary, ferocious and violent than Sound Hierarchy. Music this blistering obviously isn't for everyone, but for those who enjoy free jazz that takes not a single prisoner, this disc is highly recommended. ~ Alex Henderson