“The final ballot-shower from East to West,” as Walt Whitman put it in his poem, is upon us. In “Election Day, November, 1884,” Whitman could have been writing about another particularly contentious election — November, 2020 — which gave special relevance to Friday night’s Philadelphia Chamber Music Society concert featuring the poem and a new composition inspired by it.

The idea of brushing off the Whitman and sending it aloft on musical wings came from author and activist Lorene Cary, creator of the get-out-the-youth-vote project #VoteThatJawn. And so PCMS, which already had the Harlem and Catalyst string quartets lined up for Friday’s concert, commissioned composer Kenji Bunch to write the piece, which was given its world premiere at Friday’s concert at the American Philosophical Society.

Bunch’s stylish, upbeat work, the still small voice, doesn’t use or quote Whitman’s words — though Cary recited the poem separately before the performance — but those words are there, behind the notes.

In Whitman’s time, “America’s choosing day” did not extend to every American, Bunch writes in a preface to the score to the string octet, whose title comes from a line in the poem. The composer imagined the line as the text for “a gospel-tinged protest song," and then organized the work "as a kind of fantasy on my imaginary gospel march.”

The score directs the eight musicians to play “with unshakeable resolve,” and seven of them enter, one by one, snapping their fingers to set the rhythm. A violist comes in with a syncopated melody. And before long, the music is launched in a style recalling blues as well as what Bunch describes as the heyday of Motown recordings of the 1960s.

If Whitman seems a distant cultural cousin to this sound world, he’s not. His poem says that as mighty as Niagara, Yosemite, and Yellowstone might be, it is this day of choosing (and not with the chosen) where the real power lies.

Twice in the short poem Whitman uses the word humanity, and Bunch acknowledges this in the sound device he deploys for the piece’s most stirring moment. You might not realize what the sound is at first, but at a certain point, over the snapping, human voices rise up, and it dawns on you that the musicians themselves are humming (from behind face masks). The music swells. “Unshakeable resolve,” indeed.

Friday night’s concert came with another reminder of humanity: a live audience. PCMS has responded to the pandemic with an ambitious series of concerts, mostly at the Philosophical Society, produced for both an audience online (where I was) as well as 25 distanced listeners in the hall. The sound of applause is oddly reassuring at a time like this.

It must give the performers, too, a reason to be on their mettle, which the Harlem and Catalyst Quartets clearly were in Shostakovich’s Two Pieces for String Octet and Strum by Catalyst member Jessie Montgomery.

Whereas Bunch’s piece was there to make us confront what’s real and present in the world, the program’s final work, the Mendelssohn Octet, provided escape. The work has its introspective moments, to be sure. But we come to this music for its unalloyed joy. These two ensembles (violinist Abigail Fayette was substituting for the evening for Montgomery in the Catalyst Quartet) caught that aspect of it with enormous energy and no small degree of polish.

The concert by the Harlem Quartet and Catalyst Quartet is available online at pcmsconcerts.org now through Monday at 8 p.m. Admission is on a pay-as-you-wish basis.