If you can find some selections from Carmina Burana, I liked the couple I heard before. (Not Orff's, much older.) I'm not all too fond of monophonic and modal works though. If you can step up the time frame to some Josquin and his contemporaries, I think there's a lot of stuff there, and it's all pre enlightenment/Monteverdi/Second Practice, at the least. There's a group called Anonymous 4 that's pretty good, for the period music.