Two extremely resourceful improvisers, two women eager to engage on the playful side of free improvisation, without sacrificing the seriousness of the matter. Kuststoff presents a smorgasbord of creative techniques for trumpet and voice, articulated in moving, mesmerizing and entertaining ways. Ute Wassermann is Jaap Blonk’s female counterpart (and this is meant to be one huge compliment). Her vocabulary includes hundreds of mouth, throat and head sounds, from bird chirps to lion roars. Her range of expressions seems limitless and the way she interacts with the trumpeter, listening acutely yet remaining delightfully facetious, are akin to the tall Dutch singer. As for Birgit Ulher, her best works yet have come out in the form of duets. Her range of breath sounds, cavernous brass sounds, guttural, slippery and clickety sounds allow her to stand on the same ground as Wassermann. Both improvisers occasionally revert to the “traditional” vocabulary of their respective instrument (in “Stoff 9” for instance, a rare occasion where “common” trumpet notes are sounded), but they mostly assume each other’s role, mimic each other, and otherwise shuffle the cards (and the sounds) to the listener’s delight. Unlike several improvisers who adopt such a minutely abstract range of expression, Ulher can often be heard in the company of improvisers who eschew dead-seriousness in favor of a more fanciful approach — like Martin Klapper and Ernst Thoma. Ute Wassermann belongs to the same circle and that is why this studio meeting, recorded over two days, is such a success. The music is daring, audacious and as cutting-edge as can be, yet it engages the listener on a personal level and lets him or her enjoy it fully. Recommended.