At the height of the avant-garde of the 1950s and 1960s, Iannis Xenakis composed revolutionary works based on mathematical models and stochastic procedures, instead of the total serialism promoted by the international musical establishment. Metastaseis (1953-1954) is perhaps the best-known example of Xenakis' early efforts, though the original version known as Metastaseis A for 65 musicians is presented here by the Orchestra Sinfonica RAI in a world-premiere recording. The concept of the work is expressed in its title, suggesting a state of fluctuating tensions between change and stasis, and the individual parts coalesce into textures that transcend conventional orchestral groupings. Terretektorh (1965-1966) for 88 musicians dispersed among the public, and Nomos Gamma (1967-1968) for 98 musicians similarly deployed, are performed here by the Resident Orchestra of the Hague. They were composed with the idea of performance in the round, and the pieces may be considered a matched set, insofar as Xenakis conceived of both of them as "sonotrons" or musical particle generators, where the systematic permutation of small events determines the works' large-scale contours. Adventurous listeners familiar with Xenakis' innovative methods will appreciate the dynamic performances on this 2017 Mode release, and Arturo Tamayo's clear readings of these scores should elucidate some of the composer's most essential concepts for newcomers.
Review by Blair Sanderson