I’m still catching up with Advent material despite it being half past Christmas and nearly next year.
This is a traditional Basque carol with the text translated by Sabine Baring-Gould. Hymnary have the text and sheet music but you can also purchase it from OCP.
Once I figured out the 9/8, 12/8 time signature it was fine, but still a dog to get into BIAB.
I got to wander around King’s College when in Cambridge for a visit in January. This is their choir who weren’t there at the time: