Much the same as most traditional Christmas carols the Coventry Carol has its roots in England and was first published in print in 1591 and was originally a part of a larger musical play depicting the Christmas story.
The video below is of the Westminster Cathedral Choir singing the Coventry Carol. The individual sheet music files and full text lyrics are found farther down the page.
Lyrics to The Coventry Carol
Lully, lullay, Thou little tiny Child,Bye, bye, lully, lullay.Lullay, thou little tiny Child, Bye, bye, lully, lullay.
O sisters too, how may we do,For to preserve this dayThis poor youngling for whom we do sing. Bye, bye, lully, lullay.
Herod, the king, in his raging,Charged he hath this dayHis men of might, in his own sight, All young children to slay.
That woe is me, poor Child for Thee!And ever mourn and sigh,For thy parting neither say nor sing, Bye, bye, lully, lullay.