Josef Suk’s 30th year was a tragic one, marked by the deaths of both his young wife, Otilie, and her father, his former teacher, Antonín Dvořák. Not surprisingly, a sense of morbidity colors much of his mature output. The double-loss directly inspired Suk’s “Asrael Symphony” (named for the Angel of Death). The next step in his emotional rehabilitation was “A Summer’s Tale.” The composer seeks “a soothing balm in nature,” this Sunday at 10 pm.