Sine Qua Non is a Washington, D.C.-based quintet, rooted in American jazz but propelled by a European classical approach to composition and performance. It also incorporates elements of African, Caribbean and Latin musical traditions—“It’s really a true world music,” in the words of its founder, composer and bassist Michael Bowie. As a group, Sine Qua Non’s artistic task is to work with compositions that are built on melody, interplay and, especially, dynamics—what Bowie calls “the shape of the music.” The shape in Bowie’s music also extends to compositional structure. He doesn’t write in the typical blues and song forms—or indeed in any conventional form. “But I don’t purposely set out to write something that’s not conventional,” he says. “Nor do I purposely set out to write stuff that is purposely complicated. I just let the melody dictate what the form is going to be. I want it to be very melody-rich. And I don’t want to dumb it down—I want it to be interesting for musicians, and mostly for the people. So whatever form it takes, if it’s good and it stands up and it has shape, and it really says something, then I’m satisfied.” But there’s an additional ingredient that’s perhaps even more crucial: personality. In this, Sine Qua Non functions differently than the traditional jazz ensemble. “It’s a jazz group, in that it’s jazz musicians and they’re improvising at certain points in the music, but it’s a group that’s based in composition and not in improvisation,” says steelpan player Victor Provost—who, along with Bowie and multi-reedist Lyle Link, comprises the ensemble’s front line. “It’s not a vehicle for us to be spontaneously creative throughout the night. It’s a vehicle for us to showcase timbres, and colors.” More to the point, Sine Qua Non is about the musicians’ interpretive power, their ability to breathe life into Bowie’s writing by combining those qualities of timbre and color with the individual musicians’ abilities and creative identities. “We just use the melodic shape of what Michael writes to inject our personality into it—of course with some direction from him,” explains drummer Mark Prince. “But he likes to start with a clean canvas, leave space for something that we might introduce or offer.” “And to some extent, too, the music itself dictates,” adds Link. “You can give us playing instructions, because we’re all sensitive and we’ve played in different styles. But ultimately you just look at a piece of music and you kind of get into where the composer’s coming from, try to see what it calls for.” “You have to have big ears,” percussionist Sam Turner finishes. “It’s jazz, it’s classical, it’s Latin, it’s traditional music—and it’s having to bring all those experiences together.” Which means that, although Bowie’s vision is at its core, the band really is the music’s sine qua non—without it, the music cannot be. It’s an ensemble with tremendous synergy and intuition, bringing to the District, and a much larger world, one of the most profound creative trajectories of its time. Michael J. West is a jazz journalist in Washington, D.C.