This immaculately committed performance lasts almost four and a half hours, and shows how For Philip Guston, a trio for flutes, tuned percussion, and piano and celesta, defines the whole essence of what Feldman's late music was about. Listening to it is to become immersed in a unique musical world, one built from the simplest of four-note motifs, in which the smallest detail or change of emphasis assumes huge, expressive significance. Every so often the original motif returns, but each time its significance has shifted, because of a new context and the experience of what has happened since it was last heard. In that way Feldman maps his way around this unique, fragile musical space. It's the most extraordinary journey.