Despite the fact that much contemporary "classical" music has incorporated aspects of free improvisation for over fifty years, when instrumentalists from that area engage in it on their own, the results can be, forgive the title-alluding pun, rocky. More often than not, there's a great deal of baggage in tow, much of it doubtless subconscious, particularly dealing with vocabulary and inflection that leaves all too many strings attached to their roots, belying the "free" portion of the term.

In the case of Stones it's oddly the case only half of the time, in quite clearly delineated portions. Both Dahinden (trombone) and Kleeb (piano) have lengthy histories as new music performers, much of it documented on this same label, interpreting work from composers like Cage and Feldman to Lucier and Braxton, and generally doing it superbly. Here, they engage in a set of ten improvisations, each fairly short (ranging from almost three minutes to just over six). The pieces are titled, "Trajectory", "Territory", "Stones" (three each) and "Flying White". The problem lies with the "Trajectories" and "Territories", which are all agitated bluster, extended techniques (mostly from the trombone) and, generally speaking, indistinguishable from the kind of 70s-80s improv that Radu Malfatti (a trombonist, as it happens), legendarily described as "gabby". That horror vacui that one would have hoped had been long since dispensed with in favor of deeper listening and more considered choice in what and indeed if one plays. Make no mistake, it's all expertly performed and many might have the exact opposite reaction as this listener, but the overall impression was of the sort of sputtering, skittering, quick bursts, "rude" sounds (from the trombone) and spiky though quasi-lyrical pianistics that have been in play forever. However, if you require a cleaner, more precise version of a Conny Bauer/Alex von Schlippenbach duo, this will be right up your alley although neatness and exactitude might not be considered a desired attribute therein.

But then, we have the "Stones" and "Flying White" where just that subtler, more contemplative, more open approach is in full effect, wonderfully so. It's not merely a matter of a slower pace or a quieter demeanor; you have the full sense of space between instruments and of the instruments themselves existing in a room, not so claustrophobic and self-important. Here, even when extended techniques are in play, the lyricism reigns, the lines gently interweave and achieve an impressive plasticity. These tracks are absolutely somber and engrossing, arguably making the whole worth the price even if you object to the hyperactivity of the others. One assumes this choice was intentional on the part of Dahinden and Kleeb but I'd love to hear future expansions on the fields plowed by the "Stones".