Dating back from the 12th century, the Wexford Carol comes from the town of Enniscorthy in, yes, County Wexford, Ireland. Beginning 'Good people all, this Christmas time,' it has become familiar to many today through John Rutter's beautiful arrangement of 1978 which begins with a melodious, if frighteningly exposed, baritone solo.
From "The 50 Greatest Carols," in the December, 2008 issue of BBC Music Magazine.
I love the medieval sound of this carol. In fact, it's such a favorite that I arranged it for string quartet and used it as my wedding processional--in September! Its sound is due to the fact that it is not in a key like D major, but is rather based around an older mode called Mixolydian, where the seventh note of the scale is a half-tone flatter than it is in the modern major (or Ionian) scale. Sing Do-re-mi-fa-sol-la and then sing ti down a half-step (te), do.There is an excellent written explanation of musical modes here.
This was another carol I remember hearing Julie Andrews sing back in the 1970s, but I also like what is probably its most recent incarnation, on the cd, Songs of Joy & Peace, by Yo-Yo Ma and Friends. The track features Alison Kraus on vocals, Natalie McMaster on fiddle, and Yo-Yo Ma on ukelele (kidding).