Jazz Saved the Bassist Luke Stewart. Now He’s Working to Rescue Others.

On a Sunday afternoon in March, Luke Stewart — a bassist and composer who has gradually emerged as a galvanic force in the contemporary jazz vanguard — stood at the corner of Pine and Broadway, in Manhattan’s Financial District, running down some local history. He pointed across the street, where the American Stock Exchange sat next to Trinity Church, and noted our proximity to the former site of New York’s municipal slave market.

“You see this pattern really all over the world,” Stewart said, “where literally people are taken from the auction block, where we started, right down here to be saved in the church and sold, and then sent off to wherever they’re going.”

Stewart is wont to drop deep knowledge, whether he’s pointing out the sites of bygone jazz lofts in NoHo or spontaneously unpacking a Ravel score at the New School, where he is an adjunct professor. Sitting in the university’s performing-arts library, he traced the arcs of the notes with his fingers, posing rhetorical questions in his deep, faintly drawly voice: “What kind of emotion did the composer want?” “What was going on then?” “What is classical music, anyway?”

Stewart, 37, chuckled at the increasing loftiness of his inquiries, but his point was serious: always dig deeper — an ethos he seems eager to pass on to listeners. Introducing an interdisciplinary performance earlier in the month under his platform Union of Universal Unity, he urged the audience to “Leave here changed.”

Onstage, in each of his many projects, the tall, goateed bassist is a riveting presence. On Friday, he’ll release “Unknown Rivers,” the third album by his group Silt Trio — featuring Warren Crudup III (known as Trae) and Chad Taylor trading off on drums, as well as the tenor saxophonist Brian Settles — which makes a persuasive case for Stewart as both a composer of concise, memorable themes and a speaker-rattling powerhouse on his instrument.