The St. Lawrence String Quartet, celebrating its 20th anniversary this season, and clarinetist Todd Palmer premiere a Carnegie Hall commission from David Bruce, whose chamber works the Albany Times Union recently described as “masterful.” The Australian Chamber Orchestra performs with Andreas Scholl, a countertenor who so moved the usually raucous crowds at the Proms in London with his Handel arias that they “scarcely dared breathe” (London Times). Violinist Gil Shaham, with a group of his friends, and the period-instrument ensemble Quatuor Mosaïques also add riches to this chamber exploration par excellence.