Many string quartets start out as a family and then over time morph into an institution. As long-serving members retire, new players join in, subtly altering the sound and style until only the name remains unchanged. The Tokyo String Quartet decided to retire as a family rather than continue with further changes in its lineup. On Saturday evening, the quartet, which was founded in 1969, gave a passionate and emotionally charged performance here at the Norfolk Chamber Music Festival that the ensemble says will be its last.

On Saturday evening an audience of 700 filed into the exquisite redwood-and-cedar Music Shed of the Norfolk Chamber Music Festival to witness that graceful ending. It was gracious, too. In order to support fund-raising efforts toward much-need structural renovations of the shed, the quartet donated its fee for the evening — a gesture that was as generous as it was natural, given the ensemble’s 38-year association with this festival.

...There were plenty of surprises to be discovered in the music: the dazzling variety of effects Haydn drew from the string quartet when that medium was still in its infancy. The dark and earthy sounds the Bartok brought forth from the Tokyo’s extraordinary instruments — the musicians played on a set, on loan from the Nippon Music Foundation, that was made by Stradivarius and once belonged to Paganini — and the airy, agile playing they produced in the Debussy. They brought a bubbling springtime energy to the second movement of Debussy’s quartet that was all about light, speed and rhythmic ingenuity. The finale had autumnal colors and, sandwiched in between, was the sweetly expressive Andantino in which the players appeared to be taking their farewells from one another: Mr. Beaver and Mr. Isomura leaned in toward each other during a unison passage, the other two responded with hushed chords. There was a little tremble on Mr. Beaver’s last, dying note.

But when the Tokyo Quartet offered the Finale from Haydn’s String Quartet in G minor (Op. 74, No. 3) as an encore, the palpable sense of playfulness, curiosity and sense of fun made it feel as if they were about to start all over.