Gloria Dei Cantores is a 44-voice American choir whose nucleus is the Schola, 16 members who have used Gregorian chant in daily worship since 1976. That experience illuminates their interpretation of centuries-old liturgical chants from the four traditional Christmas masses on this recording. An educational booklet tells the story of how the celebration of Christmas grew to rival Easter after a decision by two Ecumenical Councils placed new emphasis on the role of Mary in Catholic cosmology.