“O Come, O Come Emmanuel” • Original Setting in Latin for Two Voices
Many centuries ago, this was a “trope” (poetic extension) for a Responsory.
Pope Saint Paul VI (3 April 1969): “Although the text of the Roman Gradual—at least that which concerns the singing—has not been changed, the Entrance antiphons and Communions antiphons have been revised for Masses without singing.”