Julia, I think it would be more accurate to say that Orff composed Carmina Burana in 1936, using texts from medieval poetry. I would certainly consider Carmina Burana to be a modern composition.

There's a performance of "Crudite" here:

https://www.youtube.com/watch?v=8nLb6GM7Ybs

I can't figure out who the performers are.

The Oxford Book of Carols (1928) includes 5 songs from Piae Cantiones, and there are 11 in the New Oxford Book of Carols (1992). One of these is "Flower Carol" (Tempus adest floridae), used by Neale as the melody for his "Good King Wenceslas." The Latin in these songs is fairly simple. I would suspect it was at least partly understood by many Europeans. I knew and understood many Latin hymns I sang in my youth, long before I actually took classes in Latin.

-Joe-