The old green paperback songbook (this goes way back) had melodies from a few "worldly" sources. They were purged when that pink/purple thing came out. Actually got rid of some of the best melodies.
They did say that when the pink songbook came out, and they said it again about the pink songbook when the current brown songbook came out. Makes you wonder, doesn't it? Apparently the purge of Babylonian influence wasn't complete enough the first time.