I believe that the version you want is listed as a track on this CD: Ancient Noëls / Maggie Sansone and Ensemble Galilei Label: Maggie's Music, Release Date: 1993, Catalog Number: MMCD 108; Distributor: Allegro.

... also as a track on a CD: A Victorian Noël, listed here :CLICK, and the liner notes there indicate: Bethlehem's Stall (Basque) -- Of unknown antiquity, the Basque title is "Abets zagun guziek."

Everything else I found was a different song by the same name-- two or three others, according to Google search. And nothing on the Basque name of it.

If we don't find it, but you ever do-- please post it here!

~Susan