John Shima

Mr. Xenakis, for to achieve complete victory in his "struggle for existence", would have to create something so different that to anybody else it would be totally meaningless.
Even he has not gone that far, though he has regularly traveled a long way into the desert of incoherence, often by calculating his music so as to maximize disorder. This is the main thrust of his mathematical techniques: his spinning numbers, like John Cage's coin tossings, insure that notes are chosen and ordered by blind chance, or according to processes of change that have little to do with conventional musical perception.
…..
Mr. Xenakis so often equates beauty with savagery: in his fascination with weapons and armor, for instance, with the sea or with the bulls of the Camargue. In his music virtually the whole elaborate machinery of Western composition is set aside, and we are left with a brute vocabulary of other modernists - Stravinsky, Varèse, Harrison Birtwistle - avoidance of the immediate past leads to imagined contact with the archaic.

Paul Griffiths, The New York Times, Sunday, January 26, 1997