The JACK String Quartet. (Henrik Olund)

Is there any string quartet today as flat-out brilliant as the JACK Quartet? This virtuosic young ensemble has emerged over the past decade as the go-to quartet for contemporary music, tying impeccable musicianship to intellectual ferocity and a take-no-prisoners sense of commitment — as its players (with guest pianist Eric Huebner) proved in an afternoon of new American music at the National Gallery of Art on Wednesday.

Part of the museum’s ongoing American Music Festival (which runs through March 22), the concert traced an arc from Morton Feldman’s 1950 spare, achingly delicate “Intermission 1” for solo piano to “The Dead Man,” an often brutal piece by the reigning genius of the New York avant-garde, John Zorn.

The central works on the program, though, may have been the most compelling. The program notes for “Le Journal du Corps,” a 2010 quartet by Lewis Nielson, were a little alarming — references to Frantz Fanon, “colonial imposition” and “corporate purchasing power” threatened a tedious screed. But the music itself seemed almost whispered, drawn in quiet gestures that echoed the human agonies it explored and coalesced finally into an exalting movement that had the grace of a communal prayer. In short, a work of serene dignity and subtle emotional power, as spiritual as it was political.

Eric Huebner returned for Roger Reynolds’s “imagE/piano” from 2007 — a brief piece that blends intricate construction, probing intellectual depth and sheer exuberance into a sweeping whole — and gave a perfectly calibrated reading of Stefan Wolpe’s “Form for Piano” (1959).

Some of the most high-octane music of the afternoon, though, came in David Felder’s “Stuck-stücke for String Quartet.” Exploding out of the gate, it rarely pulled back from edge-of-the-seat intensity throughout its 13 short movements, with violinist Ari Streisfeld leading a performance that left scorch marks on the ears.

The afternoon closed with a quartet from Zorn, a composer so volcanic it’s a wonder he doesn’t burst into flame. “The Dead Man” from 1990 is not exactly a walk in the park — Zorn himself describes it as “sadomasochistic” — but like all his music, it’s beautifully made, full of strange and unsettling turns, and fascinating to its bones. The JACK players turned in a richly colored and theatrical performance — at one point slashing their bows through the air like whips — that brought out the astounding range of Zorn’s astonishing imagination.

Brookes is a freelance writer.