Ut queant laxis is the Office hymn for second Vespers of the Nativity of Saint John the Baptist (June 24). The more famous of the two Gregorian melodies is attributed to Guido d'Arezzo and begins each phrase on a higher scale degree: hence the naming of the solfeggio notes after the first syllable of each line of the first verse.
Sit decus Patri, genitaeque proli
et tibi, compare utriusque virtus,
Spiritus semper, Deus unus, omni
Temporis aevo. Amen.
English translation
For thy spirit, holy John, to chasten
Lips sin-polluted, fettered tongues to loosen;
So by thy children might thy deeds of wonder
Meetly be chanted.
Lo! a swift herald, from the skies descending,
Bears to thy father promise of thy greatness;
How he shall name thee, what thy future story,
Duly revealing.
Scarcely believing message so transcendent,
Him for a season power of speech forsaketh,
Till, at thy wondrous birth, again returneth
Voice to the voiceless.
The heavenly citizens celebrate you with lauds, one God and at once triune; we also come imploring forgiveness; spare us among the redeemed.
Thou, in thy mother's womb all darkly cradled,
Knewest thy Monarch, biding in His chamber,
Whence the two parents, through their children's merits,
Mysteries uttered.
Praise to the Father, to the Son begotten,
And to the Spirit, equal power. possessing,
One God whose glory, through the lapse of ages,
Ever resoundeth.
Amen.