Sylvain Provost/Norman Lachapelle: Ni Un Ni Deux

Sonority, not tradition, centers the music on Ni Un Ni Deux. The rich blend of Norman Lachapelle's upright bass with Sylvain Provost's acoustic guitar (plus percussion help from Pierre Cormier) anchors the duo as they stretch across musical boundaries. It makes for great sounding music, if uneven jazz.

The pair sounds happy, mostly. The vibe is so pleasant on "Deux Visites" that even Provost's humming along with himself (somewhere between George Benson and Keith Jarrett) doesn't annoy me much, though I get an urge to tie-dye a tee shirt. He plucks a clear, singing sound from the guitar, closer to Segovia than Wes Montgomery — an effective contrast to Lachapelle's deep, rubbery bass tones.

Provost doesn't play jazz licks; he improvises. But when the music calls for more orthodox phrasing, on "J' R'Commence D'Arrêter" or "Bebop Butter," he can sound stiff, measuring his eighth notes in little packets of four that accent the strong beats. Sometimes he's slippery-smooth, using only chord scales and chromatics. He rarely explores the substitute harmonies most jazz musicians use to navigate through chord changes.

On "Danse D'Orphée," though, or the shimmering "Pour Jarrett," Provost phrases as he breathes, yielding looser, more organic lines. And when dark chords lead him through the Valley of the Shadow of Death despite himself, the melodies have edges, the rhythms come more urgently. On "Bunus Blues," he and Lachapelle solo together with spooky-good communication, wedging devil-notes against some nice sideways rhythms.

Provost and Lachapelle wrote the tunes on Ni Un Ni Deux, some of which, "Chemins D'Ivoire," for instance, almost glow from the pair's warm sound. But phrasing problems surface here too. "Bunus Blues," for all its clever soloing, has a clunky head built on the strong beats. The title track, a solo bass piece, overdoes a melodic idea not potent enough to be heard so many times. Lachapelle is a virtuoso soloist, but here he leaves himself little breathing room.

Despite these problems, Ni Un Ni Deux confirms Provost and Lachapelle as world-class musicians and master instrumentalists. Their freedom from tradition creates some stiff phrasing, but it also allows their telepathic interplay. It makes possible a musical range spanning the Monk-like "J' R' Commence D'Arrêter," the arcing Spanish lines of "Danse D'Orphée," and the classical serenity of "Epilogue." The duo connects through sound with a skill that overshadows stylistic manners.