For those interested in using the Advent Antiphons, I found an interesting scriptural reference for them here by Bishop Hall of Vermont in 1914.
The Antiphons are responses used in the final week of Advent that our suppose to fix our attention on the messianic promises proclaimed by the ancient prophets of Israel. There were originally used in the monastic offices in the Middle Ages, and are often called the "Greater Antiphons" or the "O Antiphons." They are presently used primarily in the daily lectionary as the verse for the gospel acclamation during this week, or as the refrain of the psalm.
Most people are more familiar with the O Antiphons today by the hymn "O come, O come Emmanuel." Each verse of the hymn parallels one of the antiphons. They add a mood of eager expectation to the liturgy that builds throughout these seven days and climaxes at Christmas.