Vocal improvisers Jaap Blonk and Maja Ratkje rifle through 18 short improvised duets in less than 45 minutes on Majaap (Kontrans). Some improv pieces top the four-minute mark, but most come in under two, and the pacing is manic throughout. Neither vocalist has any time for anything resembling conventional voice technique. Their sound instead comes from the clearing, scratching and scraping of teeth, tongue, spittle and throat. Here, also, are the sounds of intense laughter and the abstracted sounds of people jabbering over one another at high speed-just the sort of effect you expect to hear in a theater production about fat bourgeoisie. The sounds they make seem to be geared more toward artful effect than in the unpredictability of improvisation, and would probably be much better heard live anyway.