Of the 20th-century musicians who have written music for the Church, one of my favourites is Francis Poulenc (1899 - 1963). In particular, his four motets for Christmastide are a joy to listen to, a real revelation.
There are so many wonderful Christmas poems and sacred texts, but this one always moves me:
"O great mystery
and wonderful sacrament,
that beasts should see the new-born Lord
lying in a manger.
O blessed Virgin, whose womb was deemed worthy
to carry our Lord Jesus Christ.
Alleluia."
Poulenc's music - sung in this video by the choir of Westminster Cathedral - captures the great mystery of the Incarnation. This sacred text also reminds us of the great mystery and wonderful sacrament of the Eucharist which we are blessed to see on our altars and receive in our own flesh, so that we carry Him to the world.
