Rosa recently had an interesting post in which she talked a little about Hildegard von Bingen. I have never read Hildegard's writings, but I have listened to some of her music. It is lovely and enchanting, but also somewhat disorienting and unnerving. It does not calm my fears; it does not comfort me; it does not say, "I'm OK, you're OK." In a word it is holy music in exactly the same way that most of the Christian music we hear on the radio is not holy music.
Her music reminds me of CS Lewis's TILL WE HAVE FACES.