Grade: A

During its 45-year reign as one of the world’s premier chamber ensembles, the Guarneri String Quartet has seen its share of standing ovations at concert’s end. But the one showered on them Wednesday night in Gates Concert Hall was a little different.

The sold-out Friends of Chamber Music crowd knew that this would be the last opportunity to applaud this venerable musical treasure – and so the cheers were a tad more heartfelt, as if expressing gratitude for a long and irreplaceable performing career.

Wednesday’s concert, everyone understood, is part of the group’s farewell tour, which will end late next year. The grand finale was originally to take place in the spring, but the recent illness of second violinist John Dalley has caused some rescheduling, stretching out this headline-making goodbye into next fall.

Though music lovers wish Dalley the best in his battle with cancer, the fact that the quartet will continue to play just a bit longer comes as welcome news. Somehow, the world will be just a bit less wonderful when Dalley, Arnold Steinhardt, Peter Wiley and Michael Tree have played their last note together.

Before the concert began, Friends president Kathy Newman told the audience that the Guarneris had appeared here 11 times as a foursome, and once as a trio during a 40-year span. Each one of those concerts, no doubt, was an event.

What makes this ensemble so great? That’s hard to explain. Other super-groups may be more dazzling and flashy in their playing, others may inject more crowd-tickling entertainment into their act, others may impress with more charismatic personality.

But few performing groups can bring as much sheer musicality and communicativeness to the music at hand. Even at this latter stage of their performing life, the Guarneri still bring a quality of artistry and musicianship that other quartets can only envy.

Consider the one novelty on Wednesday’s program: the Second String Quartet of Hungarian composer Zoltan Kodaly. It’s an early work (written in 1918) that nimbly blends modern sonorities with traditional folk-dance melodies and rhythms. No doubt, only a handful in attendance had heard it before. The Guarneri immersed themselves in the music, crafting a performance that left a favorable impression of the music (rather than draw attention to themselves).

Earlier, the group offered a straight-ahead reading of Haydn’s galloping Rider Quartet, a piece that gave first violinist Steinhardt plenty of opportunity to strut his stuff. Tempos here were held in check, allowing the music to breathe, rather than pant – as it often does in lesser hands.

The program proper ended with Ravel’s fragrant Quartet, in a performance that often felt like a perfumed breeze wafting through a garden on a moonlit summer night. Once again, the players made Ravel the star, instead of themselves – although Wiley unintentionally became the center of attention, when a slipped tuning peg on his cello brought the sizzling finale to a screeching halt. As he retuned his instrument, violist Tree exclaimed, “Why don’t we start from the very beginning!” No one would have objected.

As a final goodbye, the Guarneri offered the short-but-poignantly sweet Andante from Mozart’s early F-major Quartet, K. 168.