The best solo wind-instrument improv is rather like a Houdini show: there are moments when you're genuinely worried if the performer will be quite all right. Listening to Fibres - an hour of fascinating, grisly soprano-sax improvisations – you have to wonder whether by the session's end Rives was stretched out on the floor hyperventilating. Its seven tracks explore three different technical/musical areas at length; each involves a single, overwhelming sound Rives unpacks systematically, as well as fleeting ghost tones and other half-audible layers of activity. The centrepiece of "Larsen et le roseau" (presented in two versions) is an atrocious high-pitched wail which on part 1 he pushes to migraine intensity; part 2, though double the length, is on the whole less harrowing. The three "Granulations" form a three-movement symphony of spit. Part 1 is thirteen minutes of controlled gargling, part 2 offers six minutes of what sounds more like sucking than blowing (so intimately recorded as to suggest a dentist's vacuum), while part 3 gets a deeper, ickier kind of clogged-drain bubbliness. In the context of this disc "Ébranlement 1" is a bit of a reprieve (a throbbing drone that's by no means unpleasant to listen to), but listeners had better not lower their guard, as "Ébranlement 2" turns out to be the harshest thing on the disc - four minutes of godawful jet-take-off screech. I recommend Fibres highly: not only is it a remarkable album - anyone who's a keen follower of solo improv ought to check it out pronto - but it's also handy to have around in case you need to clear a room.