New York-based Canadian trumpeter Steph Richards has worked both in contemporary classical, with the likes of Kronos Quartet, and in left-field jazz and improvisation with pianist Sylvie Courvoisier, among others. It’s interesting that Courvoisier is also a close collaborator with Mary Halvorson: here, Richards is straining to expand and subvert the customary registers and timbres of her horn just as much as Halvorson does the guitar. Across a dozen short vignettes, Richards follows avant-garde trumpeters like Nate Wooley and Peter Evans in the search for a new sound, in the process dealing out eerie Theremin wails, subtle smears and muttering snickers with gusto. Pianist Joshua White adds impressionistic accompaniment on semi-prepared piano, from frenzied pummelling to limpid ripples and metallic, clockwork puzzles. The most striking tracks have Richards blowing the horn into water, creating lonesome sea-dog howls and sub-aqua burbling, and even an effect somehow reminiscent of Miles’ electric wah-wah. While not an entirely new idea (John Zorn was doing something similar with sax mouthpieces back in the 1990s and, more recently, Jaimie Branch has spurted mouthfuls of water from the bell of the horn), it elevates this duo date from a standard improv summit into something considerably more mysterious.