Amy Anderson, president of Chamber Music Monterey Bay, aptly described this season’s first concert as “bittersweet.” Heard last Friday at Carmel’s Sunset Center, this was the valedictory appearance by the Guarneri Quartet, the dominant American string quartet of the last half-century. As such, the event proved to be an emotional evening for a nearly full house of chamber music aficionados, including many who traveled from the Bay Area and elsewhere.

Weary after 45 years on the road, founding members Arnold Steinhardt, John Dalley and Michael Tree decided it was time. Indeed, their once-famous intensity and sweep seemed a bit softer, especially against the robust authority of much-younger cellist Peter Wiley, a quartet member only since 2000. In the opening movement of the first of two Beethoven “late” quartets, No. 12 in E-flat, Opus 127, Steinhardt’s highly exposed first violin part revealed a few slightly out-of-tune notes and bits of rough ensemble. But by the second movement, these minor distractions had settled into the Guarneri’s trademark unity of expressive purpose. If the power of previous seasons seemed diminished, the art was every bit as fine as in the past.

Beethoven, especially late Beethoven, is every string quartet’s great test and ultimate joy. It could hardly be a surprise that the late works would figure prominently during the Guarneri’s final season. The Opus 127, the first of the late quartets, is actually the least often programmed, and here afforded an opportunity for reacquaintance. Like all the late works, it is full of surprises: the meandering departure from expected key relationships in the opening movement; the long-limbed molto cantabile variations of the– here beautifully played– adagio; the spectral trio of the scherzo and the spooky bit near the end of the finale.

By comparison, the Quartet in A Minor, Opus 132, is one of Beethoven’s most popular chamber works. Even more personal, its central adagio shows a remarkable progression of hushed hymns and joyful dances, all dedicated in gratitude to “the deity” for recovery from recent illness. (Cameo solos by first and second violins reminded all of the difference in sound between Steinhardt’s richly mellow Storioni and Dalley’s brighter 1810 Lupot.) Yet even in this great and sprawling work, one can find wit, as for example the terse Alla marcia fourth movement and the brief recitative that charges into the brusquely triumphant three-quarter-time final allegro.

As expected, and in honor of a great and lasting legacy, a standing ovation brought the four musicians back to the stage three times before a single encore was offered. It, not surprisingly, was the tender and haunting “Cavatina” from Beethoven’s Quartet in B-flat, Opus 130. One could not imagine a more perfect farewell.

Meanwhile, CMMB has just announced a new educational and outreach residency for 2008-09 by the Bay Area-based Cypress String Quartet, with a mission of “enhancing music education and fostering a deeper interest (in) and understanding of chamber music for school children and adults in our community.” They are in residence at San Jose State University and are tapped to play the world premiere of a new quartet by Kevin Puts next February at the Library of Congress. The most dynamic of local classical presenters, CMMB has attracted funding from various sources over the years. Previous to the Cypress residency, CMMB found funding for a residency by the Rackham String Quartet (about 15 years ago) that had a huge impact on area public school music programs, with significant lasting effect in Greenfield and King City.