I thought that was pretty cool, but last weekend I mentioned to a friend how much I liked it, and she started telling me about the seven O Antiphons. I'd never even heard of the word, so she explained to me that an antiphon is simply a verse or a stanza, particularly of a religious song. The seven O Antiphons are the seven verses of the hymn (there are a few different versions around; most of the English ones have just five verses I think), which each start with an appeal to the awaited Messiah, using a different title or image. The seven titles are:
- O Sapientia (Wisdom)
- O Adonai (Lord)
- O Radix Jesse (Root of Jesse)
- O Clavis David (Key of David)
- O Oriens (Dawn - often 'Day-Spring' in English versions)
- O Rex Gentium (King of the nations)
- O Emmanuel (Emmanuel - God with us)
The seventh verse also completes a reverse acrostic - that is if you read the first letter of each of the titles backwards you spell two Latin words: ero cras (I will be tomorrow), which is of course an appropriate message for Christmas Eve.
You can read more about the O Antiphons here and here.