Pianist Kate Boyd joins forces with Midsummer’s Music affiliate the Griffon String Quartet for two concerts this month. The program features Fanny Mendelssohn’s “Das Jahr, H. 385,” a rarely performed piano masterpiece that captures the essence of the changing seasons. Adding to the evening is Wolfgang Amadeus Mozart’s “Piano Quartet No. 2.” Performed by Boyd and the Griffon String Quartet, this gem of the chamber music repertoire is known for its profound emotional expression. The Griffon String Quartet is a full-time professional string quartet from September through May.