Long before presents and reindeer there was Saint Nicholas of Myra, a fourth-century bishop and patron of children, sailors and the wrongly accused, venerated in both East and West. Cappella Romana gathers music from both traditions for him: Guillaume Du Fay’s medieval motet “O Gemma lux” and the kalophonic, or beautiful-sounding, chant of the fifteenth-century composer Manuel Chrysaphes. The program closes with Arvo Pärt’s “O Holy Father Nicholas.” An evening for those who hear history in church singing, not only beauty.