BBC Symphony Orchestra and Singers / Van Steen, Queen Elizabeth Hall, London

>This was Sea Nymphs (1994), a late work in which Xenakis splits Shakespeare's words, "Full fathom five", in The Tempest, cubistically between big reverberant blocks of sound. Yet, even its effect paled in comparison with his Nuits (1967). In this searing collage of screams, shouts, chants and grunts protesting the torture of political prisoners, scarcely a conventionally pitched phrase is to be heard.

>In between, the wind and percussion of the BBC Symphony Orchestra, under the decisive Dutch conductor Jac van Steen, unloosed the brazen tirades and batterings of Intégrales (1925) by Edgard Varèse, a precursor to Xenakis in his "liberation of sound" and deployment of scientistic concepts - though, on this occasion, the formidable balance problems he sets his performers were not always solved.

>More successful in this respect was Xenakis's Shaar (1983) for 60 strings, with its mass glissandi and stamping densities attaining a single-minded monumentality that shows him at his most impressive. It was almost a pity to follow this with the multicoloured diversity of his Alex for 30 musicians, divided into three ensembles and ranging from implacable processionals to pretty folkloristic tinklings for three harps. It reminded one that the dividing line between primeval power and primitive kitsch can be tenuous.

>It proved a mistake, too, to round off the concert with an efficient, if none too numinous performance of Stravinsky's Canticum Sacrum (1956). Commissioned for St Mark's in Venice, this may be Stravinsky in his most austere, late, serial style, but the sound of precise pitches in meaningful progressions came as balm after all the clusters and densities of the Xenakis - suggesting that, for all the daring of his concepts, his ear for carrying them through remained, by comparison, pretty crude.