Plumb is the only “traditional” free improv disc in this batch of releases, an encounter between clarinetist Lori Freedman (best known as half of the duo Queen Mab with Marilyn Lerner) and trombonist Scott Thomson. It’s recorded in extreme close-up in a dry acoustic, which actually suits the music very well: the playing is plenty vivid on its own, a lot of the action taking place “inside” the sounds. The CD is, fortunately, not an extended-technique showcase, though there are plenty of odd, ear-tickling sounds to be found here. What the duo is up to is subtler than hiss-blap-brrp sonic extremism: often it’s as if they are unpacking the extraordinary sonic oddities and treasures discoverable even in fairly standard sounds on their instruments, the rasps and flutters and expressive jolts that lurk within a note. Thomson keeps to small, tactile gestures but somehow contrives to give bebop momentum even to moments of drifting near-stasis, his playing’s calm surface ruffled by countless small shivers of delight and contrariness; while the solo piece Lead shows how much mileage he can get out of quivery pirouettes and split tones — he even throws in some curt bouncing-ball melodies right out of J J Johnson. Freedman is more inclined to moments of catharsis, exploiting the bass clarinet’s sheer animal warmth or (contrarily) emitting abrupt, computery bleeps, and letting loose a huge outcry in the middle of The Plummet; but she’s also got a knack for using hisses, sighs and whispers with needle-like precision. (Nice to hear a free improv disc where the quietest moments are so intense, even passionate, never threatening to dissolve into vagueness or low-energy drift: there’s a quiet, bubbling episode at the end of Leak that will make your scalp prickle.) This is first-rate music that hardly deserves the tag “abstract”: it contains more melodic invention than a score of mainstream jazz records.