There was a time, not too long ago, when Haydn's works were considered "inferior Mozart," very boring but by a composer acknowledged for an inhuman output of musical material. The Juilliard Quartet helped in the evolution of a new insight into Hayden's work, and continued to do so last night at the Library of Congress. "The Lark" quartet Op. 64, No.5 was the subject of this revelation, and when properly exposed to the intimate and immediate organization of ideas and gestures, Mozart is quickly forgotten. The blazing finale, which wistfully flashed by, took on the dimension of a coda and the piece ended unexpectedly on an exciting, disorienting cadence.

The special addition to the evening's entertainment was guitarist Eliot Fisk. Paganini's "Terzetto concertante" Op. 68 for viola, guitar and cello appeared at first to supply the guitar with only a subservient role in the ensemble, but the later movements developed into a true chamber piece with equal but somewhat restricting guitar parts. Fisk performed excellently within the group, and provided a rubato that gave breadth to the whispering guitar sounds. "Quintet for guitar and strings" Op. 143 by Castelnuovo-Tedesco (1950) was a work more suited to displaying Fisk's fine technique. The quartet sensitively emerged from intricate and subdued guitar passages, and Fisk's playing could only add to the crispness of the Juilliard's interpretive capabilities.