Classical review: Xenakis, Music for Keyboard Instruments; Daniel Grossmann

On one level, it makes perfect sense to realise Iannis Xenakis's notoriously difficult works for solo piano and solo harpsichord using computer-controlled MIDI instruments, without the mediation of a fallible interpreter. There's no doubt that the torrents of notes in the five pieces here - Herma, Mists and Evryali, for piano, Khoai and Naama for harpsichord - are heard in these "performances" with an accuracy and clarity that no human player could hope to match. Xenakis's keyboard writing contains the most elaborate cross rhythms, irrational note values and gradations of dynamic and touch imaginable and it is compelling to hear them all presented as immaculately as this.

But it brings up the question of whether Xenakis ever intended these pieces to be realised with such scrupulous accuracy - indeed, whether the statistical calculations that lie behind so much of his music were ever meant to be an end in themselves, or were just a means to a kind of complexity in which the performer's strivings and inevitable shortcomings become inseparable from its expressive power. That said, there's no doubt that much of that visceral quality survives - the remorseless power of Khoai and the convulsive eruptions of Herma especially, and the stuttering repetitions of Naama.