Bulletin of the Transilvania University of Braşov Series VIII: Performing Arts • Vol. 15(64) No. 1 – 2022 https://doi.org/10.31926/but.shk.2022.15.64.1.13 Xenakian cello: philosophy of sound and technique. Performing Kottos Alfia Nakipbekova Abstract: The article concerns Iannis Xenakis’ approach to the expressive possibilities of the cello and some aspects of his philosophy of sound and technique investigated from the performer’s perspective. To examine these themes, the paper focuses on Kottos for solo cello (1977). As part of the interpretative space, the extra-musical element of the composition relates to the technical style and means of expression: the sound, structural clarity and physicality of playing. The technical aspect and the questions of interpretation are discussed with some references to Nomos alpha – the earlier composition for cello by Xenakis – and in the light of the mythological source and reflections on Hesiod’s cosmogony. Introduction Commissioned by a prestigious musical event (Rostropovich Competition, 1977), Kottos has rapidly established a prominent position in the cellists’ concert repertoire. In the same period Xenakis completed several important compositions, among them La légende d'Eer (Diatope) and Jonchaies for large orchestra of 108 musicians. Xenakis composed two works for lower strings before writing Kottos: Windungen, in 1976 (meaning coils, meander) for twelve cellists placed in a circle, which is notable for the use of the ‘bridge sound’ (a particular sound effect that was later employed in Kottos), and Theraps for solo double bass (the title means ‘achievement, level of conscience’). Nomos alpha appeared just over a decade earlier, in 1966, when a number of leading composers intrigued by the cello’s expressive possibilities, actively explored the so-called extended and ‘extreme’ techniques. However, to some extent, instrument was still perceived within the framework of the traditional cello repertoire. The abstract concepts that underpin Nomos alpha are embodied in new sounds unexpected from the cello. Confronted with the unknown, the listener was and is still challenged by the work on many levels – the sound, techniques and complexity of the compositional ideas. In the preface to the score Xenakis expounds the mathematical foundation of the piece: Symbolic music for solo cello, possessing an extra-temporal architecture based on the theory of groups of transformations. In it use is made of the theory of “sieves”, a theory which annexes the congruences modulo z and which is the result of an