Gregorian Chant • “How To Sing The Repercussion” (such as: Bistropha, Tristropha, etc.)
Each monastery had its own particular way of singing plainsong.
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.”