Dialogue De L'Ombre Double: Construction By Assemblage.(Pierre Boulez)(Critical Essay)(Illustration)

What is...important...is the dialectic of composition.

Pierre Boulez, Orientations

PUBLISHED IN 1985, Dialogue de l'ombre double by Pierre Boulez is scored for one live clarinet and one prerecorded clarinet, both usually performed by the same instrumentalist. The two do not play simultaneously, except for brief overlaps, until the end, when the live performer sustains a [D.sub.6]. The recorded material drives toward a cadential unison of the held pitch that finally resolves the dissonance and closes the piece. In general, though, a dialogue exists throughout the piece between the live and taped musician, with each replying to the other's musical ideas.

This dialogue is further divided into thirteen sections of "sigle initial, 6 strophes linked by 5 transitions, and sigle final...the strophes are to be played by the clarinettist on stage; the sigle initial, transitions, and sigle final are to be pre recorded ... and played back through loudspeakers in dialogue with the clarinettist on stage" (Boulez 1985). This design is shown in Example 1.

These sections are ordered in two ways, and both versions appear in the same publication. One order is the "version aux chiffres romains," and the other is the "version aux chiffres arabes." The relationship between the two versions is interesting, with the live clarinet (la clarinette premiere sur scene) playing the same strophic material in both arrangements but numbered and ordered differently. The recorded material (la clarinette double en registree) is altered only slightly in all but one section in each ordering, transition IV a V and transition 5 a 6, both unique to their respective arrangements. Sigle initial and sigle final are unchanged except for the end of initial and the beginning of final. The transitions and the sigles include slight variations at their endings, perhaps to offer better links from strophe to strophe in their particular versions. In both Roman and Arabic versions, the transitions remain coupled with the same strophes they are preceded by. Example 2 places the identical sections f rom each version side by side; the Roman version shows performance order, but the Arabic does not.

From Example 2, symmetrical properties emerge, which are shown in Example 3. The versions are like two possible recipes, each using nearly identical ingredients mixed in different manners and yielding different final results. Not that the end results would be radically different; indeed, both dialogues will leave essentially the same aural taste in the listener's ear. The exact arrangement of the music is not crucial to maintain the integrity of the whole, and other possible arrangements of the shared constituent parts might be able to stand alongside the two versions already given.

Boulez's use of a mobile structure is not unique to Dialogue; indeed, a sort of formal open-endedness is present in other works of his as well, notably the Third Piano Sonata. Describing that work, which is also divided into strophes (A, B, C, and D) unfixed in a definite performance order, Boulez writes, "each [strophe is] capable of being developed independently but on similar lines... The pagination of each strophe is mobile, independent of all the others... The work, as it unfolds, will employ only one kind of density at a time ... so that each strophe illustrates a different stage of development. In this way it will be possible to read [A.sub.2], [B.sub.1], [C.sub.3], [D.sub.4], and so on...." (Boulez 1986, 152).