Humor and irony are often apparent in this Blitzstein work, which predates the composer's better-known political-populist endeavors during the same decade. (There's a parallel here with Kurt Weill's music-theater, which followed the astringencies of his earlier concert compositions.) The four-movement quartet takes off from received forms with three quick-tempo movements in a row before a final closing Lento chorale. Compositionally, it has great confidence, and it was a masterful performance by the committed Del Sol members (violinists Rick Shinozaki and Kate Stenberg, cellist Hannah Addario-Berry, and violist Charlton Lee).

Dissonant counterpoint, eerie harmonies, and modular construction manifest themselves in various guises, including that of a weird waltz. The second movement's dotted-rhythm, pseudo-swing, and cakewalklike scherzo collides with more stentorian gestures. The third's "Presto possible," as in other movements, does not lead in the expected direction, and at times it seems to leap off compositional cliffs. It was all enough to make your hair stand on end, and a good time was had by all — including the performers, who stood, New Century-style, throughout the duration.

Hyo-shin Na's Song of the Beggars (1998) was a more modest undertaking. It is one short, single movement, which was explained as a representation of the spirit of Korean mendicants who howl their wheedling wails best when utterly ashamed of their plight. After an initial, solemn sustain there was a muscular, refreshing, and surprising caterwauling worthy of George Crumb or Elliot Carter. At other times, there was an every-person-for-themselves attitude in the style of a latter-day Charles Ives. Alas, no program notes were provided during the concert to further enlighten the audience with respect to these fine works.

The second half of the program was given over to Schubert’s massive String Quintet in C Major (1828), and Jeanrenaud joined the quartet as the music’s foundation, the lower cellist. Often, the composer handles this second player almost as a seated string-bassist, with the upper voices bowed and the lowest pizzicato. And occasionally, the first violin is in consort with this voice, with the other three remaining as an interior harmonic sandwich.

Entirely delightful, Schubert finds a maximum of textural and structural variety within received practices. And in this opus posthumous effort, he occasionally seems to go beyond the norms of his day. Indeed, there were some intriguing parallels to be made with the Blitzstein (of all works), and the Hyo-shin Na served as an apt divider. Schubert, like Richard Wagner several decades later (this is in reference to the Tristan I heard last week), takes his time but is, of course, vastly clearer. "They don't make pieces like this any more," said one audience member afterward. Well, they don't make them often.

A 50-minute monster, the Schubert is relentlessly engaging and never lets the listener down. Del Sol and Jeanrenaud were in perfect consort, and it was particularly intriguing to hear the former Kronos member in such a traditional context. Then with the encore, the traditional shot beyond to the almost archaic, in a stirring rendition by Renaissance master Josquin des Pres.