Plainchant | De profundis | Graduale Romanum, Mode II

This Gregorian chant, De Profundis, is the appointed Offertoire Proper for the Twenty-third Sunday After Pentecost, or, Thirty-third Sunday of the Novus Ordo year.
The sacred text is taken from Psalm 130:1-2
"Out of the depths have I cried unto Thee, O Lord: Lord, hear my voice."