One of the most inventive minds in 20th-century music belonged to the Czech Jew Erwin Schulhoff, whose works are all but ignored today. On Sunday, the fine chamber ensemble Concertante presented his groundbreaking String Sextet at the Merkin Concert Hall.

Schulhoff was an experimenter, working with quarter tones at the same time Charles Ives and Henry Cowell were fashioning these microintervals into crabbed compositions on this side of the ocean. A student of Max Reger, Schulhoff loved thick textures and also dabbled in dodecaphonism in the very early 1920s, even before Schoenberg unveiled his 12-tone system. A rabid leftist, he was the first — although unfortunately not the last — to set the original words of the “Communist Manifesto” to music. He thought that his honorary citizenship in the Soviet Union would allow him to escape the net of the Nazis after Prague was occupied, and so it did until Hitler invaded Russia and Schulhoff was dragged off to the camps where he died in 1942.

The sextet begins with a theme that employs all 12 notes of the chromatic scale, but the influence of Bartók seems much more profound than that of Schoenberg. This performance by Concertante was extremely moving. The group (Ittai Shapira and Xiao-Dong Wang, violins, Rachel Shapiro and Ara Gregorian, violas, and Alexis Pia Gerlach and Zvi Plesser, cellos) was totally invested in this rollercoaster ride of emotions, intensely barbaric in spots, tender in others, humorous still elsewhere. The ensemble captured the sound not of six instruments beautifully blended, such as Brahms or Mendelssohn might have wanted, but rather a half a dozen distinct lines sometimes quite discordant and segregated. Ms. Gerlach, in the especially important role of the first cellist, was quite adept at quicksilver mood changes and oddly ominous effects.

In the Tranquillo the cello becomes a sort of cosmic clock, slowing down and almost stopping in a decidedly frightening manner. In the Molto Adagio, its deep groaning recalls some of the other contemporaneous diasporan literature, such as Ernest Bloch’s A Voice in the Wilderness. The harmonic language may be a bit thorny, but the message seems eerily prescient, as Schulhoff’s eventual martyrdom bears witness. This can be difficult music to appreciate for a 21st-century audience — Ives would have called it “not for the lily-eared” — but this sensitive performance seemed to affect the crowd significantly.

The exceptional pianist Adam Neiman joined for a driving rendition of the Piano Quartet in E Flat Major of Antonin Dvorák . Imagine a large chamber work with a complex Brahmsian sound, but with every movement hinting at the folk element the way that Brahms does in the final movement of his G Minor work for the same instrumentation. Despite Mr. Neiman’s disciplined pacesetting, the somewhat more relaxed folk rhythms were omnipresent. It was impossible to forget this was Dvorák, that sunny inventor of what is essentially his own folk music, an idealized community of the mind and ear where all is pantheistic hilarity.

This was a very passionate performance and included cello playing of a different sort from the Schulhoff. Here Mr. Plesser impressed with his dexterity and yeomanlike service. At several points, the work almost seems like a cello sonata, and Mr. Plesser was up to the heavy lifting.

Also on the program was a real rarity, Dvorák’s Five Bagatelles for two violins, cello, and harmonium. All classical music is evocative of some bygone era, but this sweet and lovely music is especially atmospheric since the portable organ that provided the rather breathy basso continuo was designed for home use. It was easy to imagine families sitting around the hearth singing hymns accompanied by these accordionlike sounds that harken back to a simpler time.