i. Identification of sound materials and the processes of change which they undergo.

The opening of Verblendungen presents a single loud attack-decay gesture in which both tape and orchestra participate. There is a clear causal relationship between this attack and its subsequent continuant/decay. It is possible to view this gesture, which forms the opening three seconds of the piece, as providing an archetype, from which many aspects of the work derive and are developed, returning in extended and reversed forms. The basic nature of this gesture and its makeup is shown in figure 5, which also clearly identifies five separate, clearly identifiable types of material within it, equally shared between tape and orchestra.

The first of these is the simplest material type in both its morphology and its structural function. Played by bass drum, this noise-based attack-impulse, when it is present, consistently provides the causal start and initial energy burst for the attack-decay gesture to continue. It is repeated twelve times, varying only in dynamic (decreasing from ffff at the opening to fat its final sounding at rehearsal letter D) and in length (changing between damped and undamped modes of playing).
The second material type is on tape. An attack-decay, which is initially temporally connected with material type 1, extends its attack-impulse. Unlike material 1, it is note-based, having a clear pitch (E1) and harmonic content, which are unchanging upon repetition. Its spectral typology can be placed between harmonic spectrum and note proper. It helps to contribute, together with the bass orchestral instruments (double basses, tuba, contra-bassoon), to the sense of rooted pitch space created by the almost continuous presence of the low E, the lowest pitch present, which exists through this section of the work.
It is interesting to note that here, at the very start of the work, both tape and orchestra are participating in what might be traditionally considered each other's sound worlds: electroacoustic music most often thought of as being concerned with gesture and texture, instrumental music with pitch and melody. The tape, in material type 2, presents a pitched/harmonic note-based sound; the orchestra, in material type 1, contributes a noise-based gestural sound. This crossover helps to ensure a close relationship between the two elements, allowing them to merge, to create, together, a unified, fused, sound world of their own.
Material type 3 occurs only three times during the opening five minutes of the work but has a very important and clear structural role to play. Closely related to the previous material type, it too is pitched and has in its first instance an attack-decay profile. However it is temporally much longer, lasting at least through the first eighteen seconds of  the piece (it is not possible to identify its ending accurately as after this point it becomes obscured by other, louder sounds on tape, particularly material type 5b). Due to its relatively low volume it is not easily grasped as a separate sound even when listening to the opening electroacoustic material on its own. Unlike the previous material type it  has internal timbral variety and is not note-based, having no clearly identifiable single pitch. Rather it is best described as nodal, having identifiable pitch areas (particularly in the treble register) rather than individual pitches. Its role at the opening is supportive, helping the other tape sounds to fuse together as well as providing some timbral variety, rather than being easily individually identified. Indeed it is only later on in the piece when it returns, in its reversed form, gradually swelling from silence towards an attack cut-off point that it is clearly recognised as a separate sound type, working clearly in the foreground, that its importance emerges, marking as it does the start of both the level 5 continuant and termination phases, providing the most obvious aural clues to  these important structural points. The internal timbral changes within the sound type are not easily categorised but perhaps best described as cyclic and repetitive, with a clear sense of gestural direction and tension building towards the (future) attack point, coupled with increasing dynamic levels. This is, in part, the result of the rising pitch area, rather like a filter sweep, which occurs through this sound. Obvious connections can be made to the other rising pitch profiles which will be identified through this part of the piece. In both cases the cut-off points of this sound is followed with material type 2, which provides an associated decay.
The fourth material type, which constitutes the most important, and subsequently becomes the most developed material in this first section of the piece, is provided by the orchestra. At the start of the piece this consists of a close, dense chord which creates an inharmonic spectrum (that is, not belonging to the harmonic series) and provides the main continuant/decay portion of the opening gesture (figure 6).

The final material type identified here, provided by the tape, is a noise-based stream of sound which, at the opening, supports the main attack-decay gesture. Closer listening, particularly to the tape part alone, reveals two separate materials overlapped, both closely related in their noise-based spectral typology but having different behaviours and structural functions. The first, (5a), stays connected to the main gestural impulses, supporting them through a series of iterations either leading up to or from the main attack-impulses created by material 1. It is slightly varied in length and internal rhythmic shape through this section but always retains one of two clearly, recognisable gestural shapes:

Material type 5b has a higher frequency range and undergoes much greater changes, beginning as an effluvial/grain stream which gradually becomes more iterated until it forms a series of rhythmically irregular, but clearly defined attack-impulses (rehearsal letter E onwards), becoming more like the individual iterations within material type  5a.
A further kind of mirroring or equality can be identified in the roles played by the sound material types that tape and orchestra each contribute at the opening. Each presents material that is unchanging and which takes a supporting part in the music's unfolding (materials 1 in the orchestra and 2 and 5a on tape), as well as material which is varied and has a primary structural role to play (4 in the orchestra and 3 and 5b on tape).
A fuller description of these materials can be made by using the three spectromorphological continua previously discussed, the results of this identification are shown in figure 7. An indication of the processes of change which each of these material types undergoes in this first section of the piece is also identified here through the use of arrows, which show the trajectory of change. Absence of change is shown by vertical arrows.

The basically static nature of materials 1, 2 and 5a are clearly shown here, as is the changing nature of the remaining materials, 4 and 5b, which both exhibit changes along two axes, (moving together in the same direction along the effluvium/attack continua and in opposite directions between texture-gesture) and are fixed at opposing ends of the third, the effluvium/pitch continuum. Along this axis, there are examples of each possible spectral typology, from note proper, through harmonic and inharmonic spectra, node and noise. The description of material type 4 shown here is somewhat simplified, particularly in its description of changes along the gesture-texture axis and, given its structural importance, requires a more detailed explanation.
Within this material type it is possible to identify two kinds of instrumental role. At the opening of Verblendungen, all the pitched orchestral instruments are given the same notational instruction ( h. ffff / fff  ). Due to differences between instruments however, this same notation results in two different types of sound, one created by the percussive instruments (marimba, piano and harp) marking the attack of the opening gesture and then decreasing in volume (with their natural decay envelope), the other by the sustaining instruments (woodwind, brass and strings) which continue the gesture. Apart for two exceptions (at bar 14, middle c and at bar 25, g below middle c, both played by harp) the non-sustaining instruments double pitches played by the rest of the orchestra and so can clearly be seen to be emphasising and supporting the gestural attack, in terms of dynamics and colour. This role is continued until rehearsal letter K (3'41") where for the first time the gestural attack is made (orchestrally) only by strings, the percussive instruments having joined in the general change that this material type undergoes, moving from a gestural to a textural role. Perceptually, this change occurs gradually, in a continuous, unbroken way. However the orchestral score reveals how this achieved, with new material being introduced across the orchestra in overlapping waves, spreading amongst groups of instruments. The step-wise development of this material can be seen in figure 8, which lists the first occurrence of new figurations. This material overlaps with previously introduced material in other parts of the orchestra resulting in a layered complex texture where up to 4 or 5 different materials may be simultaneously present.
There is in fact one other sound, on tape, which occurs during this opening five minute section of the piece. It is not audible in either of the recordings used of complete performances, its sound being covered by the orchestral material, only revealing itself when the electroacoustic material is listened to on its own. This sound has not been included in the list of materials above, due to the fact that it has minor structural role to play in this section of the piece, but is mentioned here for the sake of completeness and also because it has important connections with events which occur later on in the work (particularly in the tape solo, which will be examined further on in this study). This sound occurs twice, quietly, between 3’15”-3’27” and 4’35”-4’55”, both times emerging above material type 2, having no obvious structural role, with no clear connections to be made between these two points in the piece. The end of the sound is similarly connected with material 2, the first time it stops in the same way as it begins, being obscured by material type 2, the second time it fades away just before a new attack of material 2a sounds. Its composite texture contains a number of identifiable pitches and it is the most complex sound so far on tape, clearly associated with the ongoing general shift away from gesture to texture in the orchestra. As part of this it can be seen as a development from material type 3 with its internal timbral variation.