The great O Antiphons of Advent in Western Christian tradition are chanted or recited at Evening Prayer during the last seven days before Christmas. Every antiphon begins with the exclamation ‘O’ and shapes the worship at this time. each refers to a different name for the Messiah and to Isaiah’s prophecies of his coming.
O Sapienta (O Wisdom)
O Adonai – (O Lord)
O Radix Jesse – ( O Root of Jesse)
O Clavis David – (O Key of David)
O Oriens – (O Rising Sun)
O Rex Gentium – (O King of the Nations)
For more about the antiphons listen here to O Sapienta being chanted at the Blessed Sacrament Chapel, Seattle.