Juilliard String Quartet At the Library of Congress

It's heartening that after significant changes of personnel and a 43-season residency at the Library of Congress, the Juilliard String Quartet still possesses the vitality and probing intellect heard on its earliest recordings.

The centerpiece in its Library of Congress recital Friday was String Quartet II ("The Loss and the Silence") by Argentine composer Ezequiel Viñao. A rigorous and weighty piece that straddles traditional tonality and anguished dissonance, it's not inaccessible, but it demands (and repays) concentration. The five movements cover a wide stylistic and emotional range: The first and third deconstruct 18th-century quartets and modern tango music, respectively; the second and fifth cycle obsessively through expressions of restless sorrow; and the fourth is written in a kind of jagged, propulsive minimalism. The Juilliard, which premiered the work last year, gave a scrupulous and committed reading that dazzled most in the punishing cross-rhythms of the third movement's splintered tango.

The Viñao was preceded by a reading of Schubert's "Quartettsatz" in C Minor, characterized by lashing accents and febrile tone. Beethoven's C-sharp Minor Quartet, Op. 131, which followed, unfolded in a tone of spontaneous musical conversation, where sentences would naturally break off and restart, and one instrument's line of thought would be picked up and finished by another. The Beethoven quartets have been central to the Juilliard's repertoire for more than half a century, but I can't remember hearing from it a more genial or unforced performance of this masterpiece.