“The hymn has also been attributed to St. Ambrose and to St. Gregory the Great, but without real evidence for either ascription.”
Veni Creator Spiritus
From the early Church Fathers to now.
Come, Holy Ghost, Creator blest, and in our hearts take up thy rest; come with thy grace and heavenly aid to fill the hearts which thou hast made. O Comforter, to thee we cry, thou heavenly gift of God most high, thou fount of life, and fire of love, and sweet anointing from above.
The hymn is most often ascribed to Rabanus Maurus (d. 856), Abbot of Fulda and Archbishop of Mainz; the manuscript evidence carries it back to the ninth century.
By the Middle Ages Veni Creator Spiritus is sung at Pentecost and at the Church's most solemn acts — the election of a pope, the consecration of bishops, the ordination of priests, the dedication of churches, and the opening of synods and councils.
The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.