23rd Sunday after Pentecost
Processional hymn: Hearken, Shepherd of the Sheep, 873
Recessional hymn: The King of Love, My Shepherd Is, 874
Kyriale: Mass XI, 740; Credo IV, 780
Hymn after Offertory: Languentibus in Purgatorio, chant
Communion Antiphon: Amen, Dico Vobis, Heinrich Isaac
The hymn Languentibus in Purgatorio is an excerpt from a fifty stanza poem—each ending with O Mary—attributed to Dom Juan IV de Langoueznou, abbot of the Benedictine monastery of Landevenec in the mid-fourteenth century. The chant sung at Mass only has seven verses from the greater work. Here is the first verse translated to English: The suffering souls in Purgatory, Who are being purified in excessive heat, And are tormented by severe punishment, Assist them, in your compassion, O Mary!
This Sunday’s setting of Amen, Dico Vobis by Heinrich Isaac makes use of the original Gregorian melody in the soprano voice with very little variation.
Heinrich Isaac (c.1450–1517) was a Renaissance composer from the South Netherlandish region. His output was rivaled only by Orlandus Lassus in number and variety of composition. Most notable of his collections is Choralis Constantinus which contains nearly 400 Gregorian chant based motets of propers for the Mass.