There comes a point in almost any scheduled performance by Jon Batiste when he pops up from the piano and strides into the crowd, tootling his melodica, a toylike wind instrument, with bandmates in tow. It’s a trademark shtick that happens to carry a whiff of the authentic, given Mr. Batiste’s lifelong familiarity with New Orleans second-line parades. Naturally, it was one of the factors that led to his role as bandleader on “The Late Show With Stephen Colbert,” which makes its debut on CBS on Tuesday.

Mr. Batiste, 28, has a lanky frame, a dandyish flair and a breezy disregard for genre pieties. It’s easy to picture him acclimating fast to a late-night talk show, even if the stubborn constraints of the format seem at odds with his brand of free-range spontaneity. The “love riot” — his favored term for a flash-mob-style street jam, which he facilitates through social media — is only the most literal manifestation of his drive to connect viscerally with an audience, winning over many startled listeners on the move, and at close range.

This summer he and his band, Stay Human, played the Newport Folk Festival and the Newport Jazz Festival, on consecutive weekends at Fort Adams State Park in Rhode Island. Each of their afternoon sets ended, inevitably, with a pied-piper ramble into the throng. Both sets included Mr. Batiste’s jubilant take on “If You’re Happy and You Know It” — ammunition for any killjoys inclined to distrust the earnest, infantilizing aspects of his style.

But Mr. Batiste also tailored his message and band lineup for the two festival constituencies, demonstrating a sharp attunement to context that will be crucial in his new gig. “There’s a reinvention of the role happening in many of the late-night shows right now,” he said after his jazz festival set, referring to a wave of turnover that has made bandleaders out of the comedians Fred Armisen (“Late Night With Seth Meyers”) and Reggie Watts (“The Late Late Show With James Corden”), and a household name out of the Roots, his direct competition on NBC’s “The Tonight Show” with Jimmy Fallon.