A B C D F etc. — An Ancient “Alphabetical” Hymn
This hymn by Caelius Sedulius (Christian Poet from the 5th century) has been translated into English by a Catholic priest.
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.”