T, thanks for bringing these interesting music and comments. Neither me was really sure of what an Antiphon is. Having participated in Bach's Magnificat as soloist and in the choir, I wonder if some parts of that work could be called Antiphon, it's a detail I never asked for. It seems that Bach and Vivaldi and many others developed more elaborated pieces on the basis of the more traditional and elementary liturgic songs.
Yours, Andrés Magré (Buenos Aires, Argentina)