Veni Creator Spiritus
The "Veni creator spiritus" is a 9th century Latin hymn attributed to the Benedictine monk St. Rabanus Maurus. It is used as a hymn for the Vespers of Pentecost, as well as for the Octave of Pentecost, where it is still celebrated. Since the 11th century at the latest, the Veni Creator Spiritus has also been sung at synods, ordinations and conclaves.
Come, Holy Ghost, Creator, come from thy bright heav'nly throne; come, take possession of our souls, and make them all thine own.
Thou who art called the Paraclete, best gift of God above, the living spring, the living fire, sweet unction and true love. (...)
O guide our minds with thy blest light, with love our hearts inflame; and with thy strength, which ne'er decays, confirm our mortal frame. (…)
Through thee may we the Father know, through thee th'eternal Son, and thee the Spirit of them both, thrice-blessed three in One.