The winner of the third presidential debate, indubitably: the PUBLIQuartet.

The New York-based string quartet improvised live, from a studio at “The Late Show with Stephen Colbert,” for an hour and 38 minutes, give or take a minute, throughout, and in response to, the entire debate.

The Late Show streamed the performance, along with the debate, on Facebook Live, to a steady number of between 9,000 and 10,000 viewers.

Many of them expressed strong gratitude for the accompaniment. “The quartet relates to me more than the debate ever can,” read one comment. “I think the quartet is conveying more information than Donald is,” another post said.

Improvisation is not a part of the arsenal of many classical musicians. The PUBLIQuartet, however, makes it a regular part of their shows, often under the rubric “Mind the Gap.” Improvising for the duration of what amounts to an evening-length performance is, however, a different matter. The quartet did take little breaks, often during moderator Chris Wallace’s questions; I inferred that they were being queued by an off-camera producer.

Clearly, the players came in armed with a few points of departure. Hilary Clinton’s theme was Rimsky-Korsakov’s “Scheherazade,” a musical illustration of a teller of tales, with Romantic singing string lines. Trump’s theme was “Yankee Doodle,” now bouncy, now strident. There were plenty of other quotes, from Pachelbel’s Canon to Wagner’s “Ride of the Valkyries,” which the quartet broke into when Trump was talking about foreign policy and nuclear arms.

publiquartet-publicity-shot-1To judge from the comments, a number of the listeners understood what the quartet was doing, but not all. “Too much Yankee Doodle,” commented Limor Tomer, and added later, in all caps, “NO MORE YANKEE DOODLE QUARTET!” This is notable because Tomer is the general manager of concerts and lectures at the Metropolitan Museum of Art, where the quartet is in residence this season, so her performance evaluation holds some weight. The “Scheherezade” theme was not as familiar to everyone — or, more to the point, as jangly.

There were plenty of passages not based on pre-existing music, as well: swooping downward glissandos and ominous grumblings and growlings; jagged bow-strokes; the cellist drumming on the body of her instrument with her fingers.

It’s often said that a quartet mirrors the conventions of conversation: an exchange of ideas, a handing back and forth of phrases and thoughts. At particularly contentious points in the debate, the quartet sometimes surged up in loud ensemble playing in what amounted to a kind of philosophical commentary on the actions: Both the candidates and the instruments were talking at the same time, but there was a kind of concord in the dissonance of the quartet, and an observance of the rules, that was largely absent on the stage.

The PUBLIQuartet is one of many groups experimenting with different formats for classical music; violinist Hilary Hahn, for one, recently played for a knitting group. But it took the “Late Show” to hit on this rather brilliant one: a way for classical music to perform a function, be of service, and be ornamental, at the same time. It’s too early to tell what influence this feat of imagination and endurance may have on the PUBLIQuartet’s future; their CD sales did not immediately jump on Amazon. But they generated a lot of goodwill both for themselves and for classical music on a tough night. And according to their manager, Vincent Russo at Concert Artists Guild, one presenter who was considering presenting them has decided to go ahead with it.

The PUBLIQuartet will appear at Strathmore on Nov. 3 and at the Cloisters on November 5th.