For many years, until the millennium, the lone crusader for free music in Norway, alto saxophonist/Bb clarinetist Frode Gjerstad, 75, expands his collaborations here on a rare visit to New York partnering with local pianist Matthew Shipp, 62. Both adaptable, with Shipp having played with everyone from Evan Parker and David S. Ware; and Gjerstad's creative partners ranging from Bobby Bradford to Derek Bailey, the two betray no indecision in their first meeting.

Concentrating on tensile and harsh bites from his two horns, Gjerstad usually sets up the tracks with expressive and dynamic heads, then almost instantly upends the expositions with unexpected and instant reed contortions into multiphonics, throaty squawks and split tones. Shipp's rolling piano tones counter disruptions with a variety of strategies from keyboard crashes to soundboard echoes or solid and rigorous chording. While precise, his interpretations are never less than energetic and cunning. That means if, say, clarion clarinet trills turn to near-choked beaths as on "About Freedom of Expression", the pianist rights the narrative with sympathetic chording. Or if squeezed saxophone flutters ascend to nearly opaque smears as on "About Peace", Shipp creates pacific counter lines by challenging Gjerstad's timbres with first clanging honky-tonk-like patterns and then broken octave affiliations. Elsewhere saxophone or clarinet expressions respond in kind, so that connective reed affiliations are expressed to restore linear motion alongside the pianist's unexpected dips into pedal pressure, high pitched clips or gentling motifs.

Having reached a textural synthesis of improvisational duo-think, where sudden pivots are met with almost instant appropriate sonic gestures, Shipp and Gjerstad confirm that they know how to speak musically across continents and age groups. The disc also adds another marker to each musician's history of rewarding collaborations.