The Cuarteto Latinoamericano, a string quartet with residencies in both Mexico City and Pittsburgh, opened the Mainly Mozart Festival 2006. If their first program was disappointing, they were redeemed by their second recital on Tuesday evening, which also dovetailed as the final concert of the Jewish Arts Festival. Appropriately enough for the latter, all of the composers on the program were members of The Tribe, except for everyone's favorite goyish composer, Wolfgang Amadeus Mozart.

Two of the composers on the program, Osvaldo Golijov and David Stock, are alive and productive, and both works were more engaging than the string quartet by Gabriela Ortiz Torres heard on the Mainly Mozart Festival's kick-off concert. For those of you not familiar with the contemporary music scene, Golijov (b. 1960) is probably the most acclaimed American composer of his generation, prominent enough to be the subject of a 10-day concert series at this year's Lincoln Center Festival.

Yiddishbbuk, written in 1992, became Golijov's calling card work, enabling him to snag commissions from important groups and organizations such as the Kronos Quartet. Subtitled Inscriptions for String Quartet, the work was inspired by psalms cited in Kafka's notebooks (did he make them up, or did such a book really exist?). In their original publication, the psalms were surrounded by what could possibly be musical notation, and Golijov tried to imagine what this music would sound like. The music is written in a hair-curling modern musical idiom, and while some may find it off-putting, the emotional impact of this music cannot be denied, an overall feeling of loss, a series of mournful wailings, and in the first movement, cries of terror.

Evoking terror is appropriate in the first movement of Yiddishbbuk as it commemorates three children who died at the Terezin concentration camp, their poems and artwork preserved in the rather well-known Holocaust book, I Never Saw Another Butterfly. Dozens of composers have set these poems to music or tried to evoke the book's sentiment, but none have succeeded as well as Golijov. Bows clatter col legno on strings, musical screams of anguish cut through the frightening textures, and loud, abrasive chords brutally pound away. The remaining two movements are inscribed to Isaac Bashevis Singer and Leonard Bernstein, and although Golijov's harmonies are totally modern, there is no mistaking the doleful tone of these contemporary lamentations.

Listeners familiar with Golijov's recent accessible works such as Ayre or The Passion According to St. Mark might be disturbed by the gnarly musical rhetoric of Yiddishbbuk, but many composers, myself included, think that Golijov has gone soft in these recent works. In what was Golijov's breakthrough work, The Dreams and Prayers of Isaac the Blind (1994), Golijov explored his Jewish roots more directly by magically balancing the highly emotional modernist sensibilities of Yiddishbbuk with klezmer music, a gripping, original melding of classical and ethnic culture. This listener considers it his greatest work (at least of all those available on recordings). There was a powerful individuality in his music from the early 1990s that has disappeared in his twenty-first century works; the later works are note-perfect appropriations of vernacular musical styles, but one has little sense of a single personality behind the ipod-shuffle-play-like musical diversity of Ayre or The Passion.

Like Golijov, David Stock is another composer who was writing in a modernist idiom, and began to incorporate popular and ethnic musical influences, in addition to allowing tonal chords back into his harmonic palette. In the 1970's, Stock wrote several works in which jazz and modern music co-existed. Stock taught at Antioch when avant-garde jazz composer-pianist Cecil Taylor was there, and he also did a stint at New England Conservatory where the grandfather of Third Stream music, Gunther Schuller, presided, so it's not surprising that Stock would explore that blend of styles. In the 1980's, Stock composed works that incorporated Jewish music, including a work for the same ensemble as Stravinsky's L'Histoire du Soldat which featured a clarinet part straight out of klezmer.

Unlike Golijov, who currently appears to be an uncanny musical chameleon assuming the identity of the popular styles he evokes, Stock's excursions into Jewish music are clearly those of a contemporary classical composer using popular music as source material for his compositions. This is true of Sueños de Sefarad, composed three months ago, which incorporates a number of Sephardic melodies. I'm unfamiliar with the original tunes, but they sounded intact with little elaboration or development, the variety and form created by a different type of accompaniment (based on tonal harmonies with mild dissonances added) for each melody. An unusual formal aspect of this work was that Stock never ended each melody, ending on the penultimate note instead. This created a chain of small-scale pieces, each one propelled into the next by each tune never being resolved. Does this in some way reflect on the expulsion of the Sephardim from Spain in 1492 (which Stock references in his program note)? In Stock's treatment, the Sephardic melodies never come to rest; the final note of a melody, the tonic, is often described as the "home" note in the scale, the ultimate point of arrival and rest. Not until the final section does Stock allow a melody to finally fully conclude.

Most of the melodies chosen were melancholy strains in minor modes, although Stock also used some lively tunes where major chords and fast dance tempos dominated. In a curious coincidence, Sueños de Sefarad began exactly as Gabriela Ortiz's Aroma Foliado: the violins and viola sustain a high, soft, vibratoless, tightly compacted chord, against which the cello enters with a melody. Yiddishbbuk also opens with a high, glassy, cluster, but the chord crescendos from silence to fortissimo, serving as a brief sonic diving board into a pool of loud bow-struck strings and anguished cello wailing. Coincidence? Or contemporary cliché?

This wasn't the Mainly Modern Festival, so the rest of the concert featured two teenage whiz-kids: Mozart and Felix Mendelssohn. Mozart's Divertimento in F major, K. 138 is a damn fine piece for a 16-year-old to have composed; if its three short movements don't reach the sublime heights that Mozart would attain in his mature works, it is still a pleasant work worth programming occasionally.

Mendelssohn's String Quartet in A major, Op. 13 (1827) is a different story. Here we have a long, serious work (it constitute the entire second half) that can hold its own against any other string quartet written after it up until 1893, the year of Debussy's revolutionary addition to the string quartet canon. A list of Mendelssohn's subsequent competitors in the Great String Quartet Competition includes Schumann, Brahms, Dvorak, Tchaikovsky, and Smetana. This masterpiece was written by an 18-year-old who already had the Octet for Strings and the Overture to A Midsummer Night's Dream under his belt! Any mother, Jewish or otherwise, would be proud to have a son like Felix Mendelssohn, a compositional prodigy unmatched in classical music.

The Cuarteto Latinoamericano, whose Saturday evening performance fell short of Mainly Mozart's normally impeccable standards, redeemed themselves with their playing on Tuesday. The intonation difficulties which undercut their opening night performance of Mozart were not evident. The Jewish Community Center auditorium is an intimate space, with little reverberation to warm up a musician's sound. The Cuarteto Latinoamericano played well in there throughout the evening, capturing the elegance of Mozart, the white-hot passion of Golijov, the folksiness of Stock, and the early romanticism of Mendelssohn. The only place where they didn't quite capture the mood was in the whirlwind fairy music of the third movement of Mendelssohn's quartet, which would have benefited from a lighter touch and a little more precision. If they don't merit ranking on the A-List of working string quartets on the basis of their technique, then the adventurous repertory of the Cuarteto Latinoamericano (adventurous for the United States, anyway) definitely makes them a group worth hearing in concert or on recordings.

For a copy of the program, click here.