I've been fascinated by the Latin hymns of the office since I started praying the office in Latin in the late 1990s. They for the most part have been left out of the equation in the one-volume English translation (I don't know how the four-volume English translations handle them, since I don't own one), although some of the hymns have vernacular equivalents that are in the English editions, such as "Creator of the Stars of Night" and "At the Lamb's High Feast."
I wanted to translate the Advent hymn for morning prayer, "Vox clara," so I did some poking around on the Internet and discovered the fascinating story of the "revision" of the Latin hymnody enacted by Pope Urban VIII in the 17th century. He was so imbued with the classicism of the Renaissance the considered it necessary to rewrite or have rewritten most of the hymns that had been part of the Catholic heritage for a thousand years, by such illustrious Churchmen as St. Ambrose and Prudentius! The defective translations stayed with the Church for over 300 years until the reforms of Vatican II restored, for the most part, the original versions of the hymns. Well, they got one thing right, anyway, eh? Here is an article at EWTN about Urban VIII's "reforms." Talking about imposing the spirit of the age on the life of the Church! HT preces-latinae.org.
I never did get around to translating the hymn.