Rohnert Park, pop. 40,000, is a pleasant rural community some 3,000 miles east of Carnegie Hall. It is here that Jeffrey Kahane has created an annual chamber-music series (as part of the Green Music Festival) that could be comfortably at home in any metropolis. The opening concert of the sixth season, on Friday, featured a rich program, played by extraordinary musicians in a way that was hot, to a fault, sizzling, and brilliant. The audience, filling Sonoma State University's Person Theater in larger numbers than in previous years, responded with equal fervor to everything, caught up in the event, losing some perspective in the end. Kahane opened the program (and the season) pointedly with a contemporary work, a special one, before getting to Brahms and Mendelssohn. He selected well: Osvaldo Golijov's "Last Round" is simply one of the most exciting and satisfying works in new music. As played by the St. Lawrence String Quartet, an ad-hoc quartet composed of violinists Chee-Yun and Lindsay Deutsch, violist Aloysia Friedman and cellist Alisa Weilerstein, plus Stephen Tramontozzi (contrabass), this tribute to Astor Piazzolla first rocked, then enchanted the hall. Written in 1996, to mark the death of passionate amateur pugilist Piazzolla four years before, "Last Round" opens with "Movido, urgente," a headlong rush into a sonic explosion imbued by the spirit, if not the actual presence, of the bandoneon - Golijov refraining from the use of the instrument because, he has said, "after Piazzolla, it's just not to be done." With all but the cellos standing, these always-physical musicians threw themselves into the massive, dark-hued, at times crying music, the complex, syncopated waves hitting home as authentically native to Bartok's Hungary, Janacek's Moravia, and Stravinsky's Russia as to Piazzolla's Argentina. The second movement. "Lentissimo," is a beautiful adagio, a series of simple, heartfelt variations on a Carlos Gardel song, weaving a seductive symphonic spell around the theme of "Muertes del angel." For the rest of the concert, the distracting stage mannerisms of two otherwise splendid musicians - St. Lawrence's high-kickin' Geoff Nuttall and the eye-rolling, wildly grimacing Weilerstein - were difficult not to notice, but the sweep of "Last Round" was such that nothing mattered, not even the St. Lawrence's excessively cute dark glasses for the curtain calls... of which there were four, unusual at chamber music. There was a fascinating transition to Brahms' desperately passionate serenade to Clara Schumann, the Piano Quartet in C minor, Op. 60. Kahane's thundering opening chords on the piano were answered by the excited but close-order harmonies from Chee-Yun, Weilerstein, and the exceptional violist Nokuthula Ngwenyama (the California-born daughter of a Zimbabwean father and a Japanese mother). The Brahms Allegro and Scherzo continued, as it were, the spirit of Golijov's "Movido, urgente," and then the Andante picked up on the sound and quiet beauty of Golijov's Lentissimo, parallel structures across different worlds, more than a century apart, creating magic in the hall. Seemingly unnoticed by the excited audience, the concert's concluding work, the Mendelssohn Octet in E-flat major, was a well-performed miscalculation. The Golijov-Brahms equation was carried too far with a "hot," dramatic reading of the work that - like so much of Mendelssohn's music - requires more light than heat, more butterfly wings than the lion's roar. The Allegro was simply too heavy, the Andante actually showed some sawing away at the strings, there was a partially successful attempt to capture the fleeting grace of the Scherzo, but the Presto ranged with too many boots in the peasants' dance to an unseemly race to the finish line. And yet, individual performances shined even as the ensemble didn't reach the heights scaled in the first two pieces. St. Lawrence second violinist Barry Shiffman, violist Lesley Robertson, and cellist Chris Costanza delivered solid value, as usual. In the Mendelssohn, and unfailingly throughout the evening, Chee-Yun played with focus and grace, providing a point of reference to the evening's brilliant debut, that of 19-year-old Deutsch. Not so much senior in years as having the advantage of a long and distinguished career, Chee-Yun's security and mastery "comes naturally," but the tall and thin Deutsch (reportedly a devoted handball player!) surprised and delighted with her equal, mannerism-free concentration, verging on serenity, showing uncanny maturity even during the most physical and demanding passages. Kahane - whose playing in the Brahms was remarkable even against what one expects from this prodigious pianist - has been long advocating both Golijov and Deutsch. Friday night served as a big "I told you so!" for Kahane. By the way, the departing music director of the Santa Rosa Symphony (for Denver) promised he will stay with Green Music Festival, continuing with this spectacular chamber-music series. The 2005 series continues Sunday, with Chee-Yun and Deutsch in the Prokofiev C Major Sonata for Two Violins, the St. Lawrence and Ngwenyama in the Mozart String Quintet in D Major, and Chee-Yun, Weilerstein, and pianist Jon Kimura Parker in Tchaikovsky's Piano Trio in A minor. On July 12, Kahane and Parker will give a two-piano recital, of Schubert, Gershwin and Rachmaninoff; on July 14, Kahane and Ngwenyama will play the Schumann "Fairy Tales for Viola and Piano," cellist Peter Wyrick joins Deutsch for the Kodaly Duo, Op. 7, Dvorak's Piano Quartet in E-flat Major ending the series, with Deutsch, Ngwenyama, Wyrick and Kahane. A new piano series follows, Kahane performing Bach's "Goldberg Variations" on July 17, Fred Hersch playing contemporary jazz on July 23, and Gonzalo Rubalcaba presenting Afro-Cuban Jazz on July 30. See http://www.sonoma.edu/greenmusicfestival/. Janos Gereben/SF www.sfcv.org [log in to unmask]