Barber’s famous elegy, the quietly powerful and reflective Adagio for Strings is the perfect prelude for Jennifer Koh’s performance of Mackey’s Beautiful Passing, a tribute to his mother’s life and strength. The violin is once again the protagonist, this time weaving its sensuous melody as Scheherazade in Rimsky-Korsakov’s colorful portrait of a sultan’s wife, who spins tales of Arabian nights.