The title seems to say it all: this is music of pure form, embodying an all-embracing system by which, Boulez has said, ''we are freed from all melody, all harmony and all counterpoint''. We are nevertheless not freed from all echoes of the past. Without completely new ears we may find ourselves hearing hints of regular rhythmic patterns in the middle of the second piece from Book 1 (1952) as well as an unmistakable cadence at the end. As for Book 2 (1961), cadence is even more explicit in the long sustained note that ends the first piece, while in the second the ghost of Ravel's ''Scarbo'' materializes in the menacing rumbles of the final stages. System is giving way to expression—yielding to melody, harmony and even counterpoint.
Structures, a crucial work in the Boulez canon, has rarely been performed complete, and this recording, when new on LP, was indispensable to devotees of the avant-garde, as well as to anyone curious about where modern music might be heading. Now it has the quality of an historical document, the playing confident and clear, the recording close but natural. Wergo remain sublimely indifferent to commerce (the short playing time) and to the needs of listeners: here the German reader alone gets reasonably extensive notes, and the English reader will do better to turn up the appropriate section in Dominique Jameux's study of Boulez (Faber & Faber, 1991). Yet Structures is an essential document in the history of twentieth-century music, and has been unavailable on disc for far too long.'