Two hundred scholars and musicians from around the world gathered in Paine Concert Hall last weekend for a two-day symposium on Arnold Schoenberg's string quartets and string trio. Scholarly presentations were interspersed with performances by the renowned Mendelssohn and Juilliard string quartets.

The event was organized by James Edward Ditson Professor of Music Reinhold Brinkmann, a noted Schoenberg scholar, and was presented by the Department of Music on Friday and Saturday, Feb. 26 and 27, in honor of David Lewin, Walter W. Naumburg Professor of Music.

Alongside the quartets of Bartók and Shostakovich, Schoenberg's music for string ensemble stands as one of the monumental cycles of our century. Although few in number, these works more than compensate in sheer weight. The music fairly explodes with restless creative energy. Indeed, one of the complaints Schoenberg often heard from the critics of his time was that he tried to make the quartet do the work of an orchestra.

The rare opportunity to hear these pieces together gave listeners a chance to trace the entire arc of Schoenberg's career.

The stage was set for the weekend's journey by a performance of Schoenberg's early string sextet, Verklärte Nacht, Op. 4 (1899), by students from Robert Levin's undergraduate performance seminar, Music 180. Written in the lush, late-Romantic style that was Schoenberg's musical inheritance and point of departure, this gorgeous fantasy breathes the hothouse atmosphere of fin-de-siecle Vienna.

The performance by Susan Koo '99 and Eileen Woo '01, violins, Sarah Darling '01 and Dana Lawson '01, violas, and Albert Pan '00 and Kate Bennett '02, cellos, was nothing short of astonishing -- beautifully played and perfectly balanced in its textures. Remarkably, only one of the students is a music concentrator. "It's a testament to the talent we have here in the student body at Harvard," says Brinkmann.

The first two string quartets, from 1905 and 1908, respectively, found Schoenberg gradually loosening the constraints of traditional tonal harmony and, in the process, forging a new musical language for the new century. By the end of the second quartet, he had dispensed with key signatures entirely.

The Mendelssohn Quartet delivered a masterful performance of the Quartet No. 1, Op. 7, on Friday night. Schoenberg once said of this feverishly ambitious work that it brought together all the musical strands of his time. It's the longest of his quartets, and in some ways the hardest to pull off. The Mendelssohn's account drew cheers from a very discriminating audience.

Harvard has enjoyed a special relationship with the Mendelssohn Quartet, who are in residence here under the auspices of the Blodgett Artist-in-Residence program for four weeks of coaching, teaching, and performing.

For Quartet No. 2, Op. 10, the group was joined by new music diva Susan Narucki to sing the verses of Stefan George that Schoenberg set in the final two movements. Narucki is one of only a handful of truly world-class vocalists who specialize in the music of our own time, and her presence on stage added a dash of glamour to the weekend's proceedings.

Narucki's entry on the line "Ich fühle luft von anderem planeten" (I feel the air of another planet) was chilling, her exquisite, dark-hued soprano floating like ether over the weightless harmonic world of the final movement.

Schoenberg spent nearly two decades exploring this new universe of atonality before writing another string quartet. The third and fourth quartets of 1927 and 1936, respectively, showed the composer inventing and consolidating an entirely new structural principle of composition, the so-called twelve-tone method.

It was a rare treat to see the Juilliard Quartet in a space as intimate as Paine Hall. The group is clearly committed to this repertoire and delivered fiercely gripping performances of these last two quartets and the string trio.

The Juilliard's interpretations emphasized the continuity in these mature works with the Expressionist aesthetic of Schoenberg's youth. There is another side to these pieces, though, which several speakers identified as a "neo- classical" spirit. In fact, Brinkmann argued that Schoenberg was here looking back even beyond Beethoven, to Mozart and Haydn. Paradoxically, it's precisely in his most radical works that Schoenberg is closest to tradition.

The String Trio, Op. 45, was originally commissioned by Harvard's Music Department in 1946 and premiered at a special concert in Sanders Theatre. It's an extraordinary work -- in ways a more personal expression than the quartets -- written when the composer was recovering from a nearly fatal heart attack. This homecoming performance by members of the Juilliard Quartet was a tour de force.

It's sobering to reflect that Schoenberg, whose innovations set the terms of aesthetic debate for so much of 20th-century music, died nearly 50 years ago. What seems clear at this remove is just how deeply his music is rooted in the Germanic tradition. Once reviled as an Oedipal destroyer in his native Vienna, the revolutionary turned out to be the most loyal son -- as Schoenberg himself always insisted.