It's hard to name more than a handful of trombonists working in free improv - Alan Tomlinson and Conny Bauer spring to mind - but, as Sarah Gail Brand amply demonstrates here, that's a shame. In her hands, the 'bone sings and swoons, sliding from light-lipped peals to fruity bluster with easy aplomb. She sets out her wares most clearly in a series of stripped back duos and trios: twinning a strangled yelp with Beresford's purring electronics; and rubbing a slippery banana skin against Edwards' pinging and scraping of the double-bass. But it's the three much longer quartet pieces that contain the real meat. Opening track, A Constant Quality’, begins by billowing in and out of focus, with scattered piano chords and a smouldering, subdued rhythm section, then slots into a higher gear with heavy bass thrumming and the metallic tinkle of a prepared piano, before settling into a pool of calm with plangent gongs, ringing tones and Brand's windy shushing. In all, the album is a satisfyingly exploratory and egalitarian date from four seasoned pros - but it's Brand's fearless chops that really shine.