Xenakis' striking use of an extensive array of non-standard (and standard) sound producing techniques for the string players was a singular element that radicalized the sound of his works for larger ensembles. Interestingly Krzysztof Penderecki came to a string sound (and an overall trajectory) similar to Xenakis when he set about composing a seminal set of works in his early to mid-period. Yet we can presume he composed more in a cognitive-intuitive mode. Be that as it may the two composers very much share affinities and that can especially be seen-heard in their string writing.
I've been thinking about all this for a while, so when cellist virtuoso Wiktor Kociuban set out to record Penderecki and Xenakis's Complete Works for Cello Solo (Dux 0957) in one CD volume, I was very much ready for it. It has marvelous performances of Penderecki's "Capriccio for Siegfried Palm," Xenakis' "Kottos" and "Nomos alpha," all of which deftly create universes of standard and non-standard cello sounds in all the ways alluded to above, and yet they very much each hang together as music, excellent groundbreaking music for cello.
A very substantial bonus comes with the inclusion of later Penderecki solo cello works, most of which are on the more melodic side. They are "Per Slava," "Violincello totale," and the "Suite." These are great to have and Kociuban gives them an expressive cello poeticism wholly appropriate.
Kociuban does the music full justice. He has a beautifully rich conventional tone and and at the same time has mastered the difficult expanded techniques of the more avant works, playing those works with a distinct continuity, a phrasing flow that enables the music to come across as totalized, unified utterances and not stitched together sound events that feel like pastiches. Not here.
It is a marvelous set of performances and the music still sounds vital. Bravo!