Harrison Birtwistle's highly abstract music is not for everyone. It tears itself into component sounds and asks the listener to re-assemble them into something greater than their sum. It takes work. But the composer has a committed champion in the Nash Ensemble, and those who want to immerse themselves in Birtwistle's universe of musical gesture should be very satisfied with the group's 2002 Black Box release The Woman and the Hare. The members of the ensemble lavish each individual note with texture, articulation, nuance, and shading -- scaling their performance to the vision of the composer. In the vocal selections, soprano Claron McFadden follows suit, prioritizing crystalline clarity and atmosphere over more conventional lyricism and integrating her sound into the ensemble. The two major vocal works on the album are The Woman and the Hare and the Entr'actes and Sappho Fragments. In the first, Birtwistle gives the bulk of David Harsent's text to a narrator, performed on the album with just the right mixture of detachment and sincerity by Julia Watson. This division of labor between two voices -- one sung, one spoken -- adds to the duality of the piece, which hovers somewhere between memory and narrative. The Sappho Fragments are so fragmented (both musically and textually) in Birtwistle's setting that the words are not so much illuminated through music as they are treated as a canvas to be sparingly dabbed with color. The two non-vocal selections, Duets for Storab, for two flutes, and An Interrupted Endless Melody, for oboe and piano, are both superbly performed. Because they are purely instrumental works, they succeed more readily on their own than do the sung works on the album; the listener is free to focus on the interplay of rhythm, color, and gesture without grappling with fleeting snippets of text.