The Southbank's annual Ether Festival, exploring innovative and multi-disciplinary approaches to contemporary music, includes this year a Xenakis weekend (perhaps timed to mark the tenth anniversary of the composer's death), of which this concert is a part; following the Barbican's "Total Immersion" day dedicated to him two years ago, there seems to be a bit of a vogue for Xenakis in London at the moment. I'm no aficionado, but have always been intrigued by his unique background as an architect and mathematician who applied the same structural principles to composition, and grateful that the resulting music doesn't sound remotely as sterile as one might imagine — in fact far less so, to my mind, than what one might call the pseudo-mathematical approach of total serialism.