The other day I found this touching piece, by composer Morten Lauridsen.
O magnum mysterium
et admirabile sacramentum,
ut animalia viderent
Dominum natum,
jacentem in præsepio.
Beata virgo, cujus viscera
meruerunt portare
Dominum Christum, Alleluia!
Translation:
O great mystery
and wondrous sacrament,
that animals should see
the newborn Lord
lying in their manger.
Blessed is the Virgin
whose womb was worthy
to bear the Lord Jesus Christ.
Alleluia!
Alleluia, indeed. Thank you, Mr. Lauridsen, for this lovely composition. I think this will be what part of Heaven will sound like. For me, a measure of Advent Grace.