Over a span of 40 years, the pianist Katherine Collier and the violist Yizhak Schotten have cultivated a winning formula: chamber music among friends. Founded at the resort of Kapulua, the festival has for the past quarter century made its home in some of the Valley Isle’s most beloved historic churches. The series opens upcountry at the stately Gothic Revival Makawao Union Church. The unassuming Keawala’i Congregational Church, hidden away by the sea on a forgotten sideroad in fashionable Makena, hosts three of this season’s concerts, while the fifth concert resounds at the Wananalua Congregational Church in faraway rural Hana. Nine international soloists in constantly shifting constellations offer winningly curated selections by Haydn, Mozart, Schubert, Bottesini, Brahms, Dvořák, and the Ukrainian-born Reinhold Glière. —Matthew Gurewitsch