For the first time in many years, the St. Lawrence Quartet wasn’t around for the first week of the festival’s chamber series, although violinist Geoff Nuttall has been here as host. They all showed up Saturday for the 1 p.m. concert.

Cellist Chris Costanza arrived Friday to show what he could do with a Bach suite — since, after all, he recently recorded all six — and he and pianist Pedja Muzijevic started the Saturday concert with Debussy’s Sonata for Cello and Piano. This is one of the six sonatas the composer started writing in his 50s in part to distance himself from the “impressionist” label pinned on him; they are much more focused and classical. In keeping with the death theme of this year’s festival, it should be noted Debussy finished only three of the six before he died.

The concert traveled from France to Argentina for a lively, but mostly serious 1945 duo for flute and oboe by Alberto Ginastera, marking the first appearance in the series this year by popular flautist Tara Helen O’Connor.

The whole St. Lawrence crew took to the stage for Beethoven’s String Quartet in F Major, Op. 59 No. 1 in which the composer made several bold statements with its length of 40 minutes (twice the length of his earlier pieces), the complexity of each part and the level of group interaction. It was a groundbreaking work for the 36-year-old Beethoven who wasn’t yet widely known and had only begun composing eight years earlier.

Needless to say, St. Lawrence was up to the job of doing this important piece justice and received a deserved warm welcome home.