On Saturday before Christmas, we went to The Cloisters at Fort Tryon Park, NY, which houses the bulk of the Medieval collection of the Met Museum. We went there mainly to listen to a concert by the Pomerium, an a cappella group which sings Gregorian chants and Renaissance music. Samples of their work.
The concert was mostly Gregorian chants and their Renaissance elaborations. One was “A solis ortus cardine,” the text by the early fifth century Christian poet Caelius Sedulius, best known for his Carmen paschale.
From the 1911 Encyclopedia Britannica:
SEDULIUS, COELIUS or Caelius (a praenomen of doubtful authenticity), a Christian poet of the first half of the 5th century, is termed a presbyter by Isidore of Seville and in the Gelasian decree.
He must not be confused with Sedulius the Irish-Scot grammarian of the 9th century. His fame rests mainly upon a long poem, Carmen paschale, based on the four gospels. In style a bombastic imitator of Virgil, he shows, nevertheless, a certain freedom in the handling of the Biblical story, and the poem soon became a quarry for the minor poets. A hymn by Sedulius in honour of Christ, consisting of twenty-three quatrains of iambic dimeters, has partly passed into the liturgy, the first seven quatrains forming the Christmas hymn A solis ortus cardine, and some later ones the Epiphany hymn, Hostis Herodes impie. A Veteris et novi Testamenti collatio in elegiac couplets has also come down, but we have Rio grounds for ascribing to him the Virgilian cento, De verbi incarnatione. Sedulius's works were edited by F. Arevalo (Rome, 1794), reprinted in J. P. Migne's Patrol. Lat. vol. xix.; and finally by J. Huemer (Vienna, 1885). See J. Huemer, De Sedulii poetae vita et scriptis commentatio (Vienna, 1878); M. Manitius, Geschichte der christlich-lateinischen Poesie (Stuttgart, 1891); Teuffel-Schwabe, Hist. of Roman Lit. (Eng. trans.), 473; Herzog-Hauck, Realencyklopadie fur protestantische Theologie, xviii. (Leipzig, 1906); Smith and Wace, Dictionary of Christian Biography (1887).
There is also the Catholic Encyclopedia.
The complete hymn in Latin A solis ortus cardine is at the Latin Library. It is written in alphabetical sequence, from A to Z.
The Christmas hymn as sung in concert goes from A to G with an added J quatrain (sometimes I) that seems to have been inserted later.
Jesus (Iesu), tibi sit gloria,
qui natus es de Virgine,
cum Patre et almo Spiritu,
in sempiterna saecula. Amen.
A similar text is used in the Chorale Cantata by Johann Sebastian Bach, Christum wir sollen loben schon, BWV 121, (from Welcome to the World of Recorded Bach Cantatas). This will give you the English translation of the Chorale.
There are many version of the cantata available, here is one, Bach: Cantatas, BWV 119-121 by the Stuttgart Bach Collegium.
JSTOR, for those who have access, has The Manuscripts of Sedulius a Provisional Handlist, Carl P. E. Springer Transactions of the American Philosophical Society New Ser., Vol. 85, No. 5 (1995), pp. i-xxii+1-244 (266 pages!)
Needless to say, all of us thoroughly enjoyed the concert.