 However, because of the forcible wind and timpani writing, a greater weight of strings is needed.Throughout the work the composer explores resonances inherent in a ‘cluster’ harmony which is introduced in horizontal form at the very outset of the work – a very dramatic opening from the bassoons, cellos and double basses, characterised by a heavy, accented dotted rhythm and the upward leap of a fifth and descent by a sixth.The notes of this theme, if spaced out in a single octave, contained every semitone from A up to D. The top three notes (C, C sharp, and D) are of great importance to the work, and each dominates in turn – C at the beginning, D in the middle, and C sharp at the end.