Jennifer Gregory Miller writes on Family in Feast and Feria about a book she ran across called The Ageless Story by Lauren Ford from 1939. It was the 1940 Caldecott Honor Book. It is a children's book about the Gospels complete with Gregorian chant Antiphons. Many things seem striking here but the introductory letter is particularly so. The illustrator explains her love of chant and offers a perspective that was widely shared by many before the war: the belief that the whole world would be singing chant in a few decades.
Please have a look at this interesting discovery.