CAMBRIDGE — Christmas privileges traditions, the older the better, anchors for what can be the most frantic of holidays. Blue Heron, Scott Metcalfe’s agile and refined early-music choir, can certainly invoke history: Their Friday Christmas concert at First Church in Cambridge focused on 15th-century France and Burgundy, a venerably rich repertoire. It’s a program the group has presented, with slight variations, in years past, and one revived, as Metcalfe noted in the program book, with the hope of communicating the joy of singing it again, here, now. But it also traded on the allure of Christmases (long) past.
A sense of archaic ritual, for instance, informed both staging and music. A gradual brightening from dim candlelight to a fully illuminated church marked the procession from Advent to Christmas. Jacob Obrecht’s “Factor orbis” and Josquin Desprez’s “O virgo virginum” were ceremonially announced by the chant melodies around which each motet wove its counterpoint. A hymn (“Conditor alme siderum”) and a sequence (“Letabundus”) by Guillaume Du Fay alternated verses between upstage circles singing plainchant and downstage trios offering ornate embellishment.