Struktur is not divided into movements. However, in fact, major structures alternate with each other. The form of the work mainly results from utilising a number of extended techniques. Sound types or groups were defined for each formal section and then formulated in detail. The sound group-technique may be clarified by means of the beginning of the piece: in terms of the wind instruments, the work starts by focussing on the speaking and playing technique. Hence noises created with the mouth are coloured by the fingered pitches. Here the wind instruments only articulate fricatives (cf. the International Phonetic Alphabet) while the headjoint, mouthpiece or reed was previously detached. At the same time, common harmonics form the sound group of the string instruments in the beginning of this section. When the harp and piano start articulating the sound group clusters, common tones and percussive effects, the sonic output of the string instruments is extended. From this point on, muted string sounds, and hence grinding noises of different brightness levels, are additionally produced. Moreover, the wind instruments stop playing at this point. After a while, the woodwinds come in, followed by the brass instruments. The woodwinds re-attach their headjoint, mouthpiece or reed step by step. Once this action has been executed, the air and tone technique replaces the technique referred to as speaking and playing. This means that from this point on, normal tone production is complemented by the articulation of noises. When the woodwinds start playing again, some of the string instruments commence blurring the harmonic pitches by using the wood of the bow (col legno tratto). Thus the clear structure of the piece is achieved by utilising sound groups in a uniform manner.