An "O" antiphon is a short passage that is sung or recited before the Magnificat during Evening Prayer in the Liturgy of the Hours. The seven antiphons, which appear in the liturgy in the days immediately preceding Christmas are called the "O" antiphons because each one, in its original wording, begins with an impassioned "O....." and then proceeds to call out to the hoped-for Messiah. The seven verses of the familiar Advent hymn "O Come, O Come, Emmanuel" are based on these antiphons. (Taken from the RCIA training book with permission, Advent - page 2)
In this months The Catholic Answer, editor Matthew Bunson, D.Min., M.Div., writes," The O Antiphons and a song like "O Come, O Come, Emmanuel" point to what then Cardinal Joseph Ratzinger, now Pope Benedict XVI, called the very connection between memory and hope. The then future pope noted: "Advent's intention is to awaken the most profound and basic emotional memory within us, namely, the memory of the God who became a child. This is a healing memory; it brings hope. It is the beautiful task of Advent to awaken in all of us memories of goodness and thus to open doors of hope" (Seek That Which Is Above," 1986)."
Perhaps you are already familiar with the O Antiphons or maybe you have never heard of them before. Advent is the perfect time to become familiar with them or to rediscover their beautiful meanings or memories, as Pope Benedict XVI so wonderfully put it. There are so many options to incorporate these into your Advent season. You could recite them within the Liturgy of the Hours, read them as a family and then discuss their meanings, or quietly read them for your own personal time of reflection and incorporate Lectio Divina. There is no right or wrong way, only a way to bring yourself closer to Christ during the preparation season of Advent.
To the right of this article, I have included a link titled, "O Antiphons". This link will bring you to the USCCB (United States Conference of Catholic Bishops) website. Here you will find all the O Antiphons listed and some history.