Negotiating the space between tonal composition and anything-can-happen improvisation, Dave Douglas's "straightahead" quartet continues to develop its original, identifiable sound. Only one of the trumpeter's many projects, this group released Magic Triangle (Arabesque) in 1998, and they've followed it up with something similar but better. Loose, natural interplay is the name of the game here, and Leap of Faith finds the quartet even more loose and natural than last time around. Douglas's writing also seems more varied and inventive.

Douglas has found a perfect partner in tenor saxophonist Chris Potter. Their precise-yet-unforced interplay recalls legendary frontlines like Joe Henderson and Kenny Dorham, or Ornette Coleman and Don Cherry. Douglas has a way with wry, enigmatic two-part harmonies, which Potter interprets masterfully. Timbral variations are also a key component of Douglas's compositional repertoire—dig the central motif of "Continental Divide," the final note of "Emmenthaler," the pregnant pauses during "Western Haiku." Bassist James Genus and drummer Ben Perowsky frame the two-horn attack brilliantly, swinging furiously on "Leap of Faith," "Igneous," and "Euro Disney," or floating subtly around the edges of "Another Country." Perowsky's drum-n-bass-inspired groove on "Millennium Bug" is one of the album's top highlights, and not the first time the drummer has pushed jazz into the mad phat zone: take a listen to "Janitor" from last year's Ben Perowsky Trio (Jazz Key Records).

Douglas's debt to the tradition is clear: he begins Magic Triangle quoting "C Jam Blues" and ends Leap of Faith with the famous closing phrase of "The Theme." But this is anything but a bebop recital. There's no comping instrument, giving the music a spare, harmonically ambiguous flavor. Tempos are established and just as soon abandoned, interrupted by montage-like ensemble passages or melodic fragments. Douglas and Potter take turns soloing, with one often playing background lines to support the other. But suddenly a background line might break out and become the dominant voice. Hearing these performances live, an audience would not quite know when to applaud. And that seems to be Douglas' intention: to upend the conventional, almost ritualized aspects of jazz performance, even while building upon the best of what the tradition has to offer.