On Kunststoff, the classically trained vocalist Ute Wasserman and the excellent trumpeter Birgit Ulher deliver ten dense improvisations in exactly an hour. Ulher – who has recorded some interesting duos previously – works in much the same non-idiomatic trumpet range as Ruth Barberán (below): sudden pops, radiator hisses, flutters, and gurgles. Wasserman’s vocals are ridiculously expressive, ranging from the brassy inventiveness of Phil Minton to the perplexing theatricality of David Moss to the warped instrumentalism of Jaap Blonk. There is fierce, quicksilver dialogue, deep empathy, and an abundance of space/respect on this recording. They seem to speak in a private language that might come from birdlike insects or subterranean creatures: one hears creaks, croaks, wails, whistles, kissy noises, and wet rattles – sometimes all in a single track! Very occasionally the music hints at familiarity: on “Stoff 2” and “Stoff 4,” for example, you feel as if you’re listening in on a bagatelle from Pluto. But for much of this disc the feel is muted and somewhat alien, though there is good dynamic and expressive range. I think it would be a better record if it were shorter and tighter – an hour seems somewhat too long. And the duo’s tendency to resort at times to echolalia and mimesis, a pet peeve of mine in improv music, at times is wearying (though, given what this demands Wasserman do with her voice, I’m inclined to overlook it). But taken a track or three at a time, one can’t help but be dazzled by the exchanges and by the variety of sounds.