One of the most widely used hymns in the Church, Veni, Creator Spiritus (Come, Holy Spirit) is attributed to Rabanus Maurus (776-856), Archbishop of Mainz.
This hymn is traditionally sung in the liturgy for the Solemnity of Pentecost, and other occasions when the Holy Spirit is solemnly invoked. The Veni, Creator Spiritus is also the official opening prayer for Church councils and synods.
A partial indulgence is granted to the faithful who devoutly recite the hymn, and a plenary indulgence if recited publicly in church on the 1st of January and on Pentecost.
Here is the traditional prayer:
Veni, Creator Spiritus
Come, Holy Spirit, Creator blest,
and in our souls 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,
O heavenly gift of God Most High,
O fount of life and fire of love,
and sweet anointing from above.
Thou in Thy sevenfold gifts are known;
Thou, finger of God's hand we own;
Thou, promise of the Father, Thou
Who dost the tongue with power imbue.
Kindle our sense from above,
and make our hearts o'erflow with love;
with patience firm and virtue high
the weakness of our flesh supply.
Far from us drive the foe we dread,
and grant us Thy peace instead;
so shall we not, with Thee for guide,
turn from the path of life aside.
Oh, may Thy grace on us bestow
the Father and the Son to know;
and Thee, through endless times confessed,
of both the eternal Spirit blest.
Now to the Father and the Son,
Who rose from death, be glory given,
with Thou, O Holy Comforter,
henceforth by all in earth and heaven.