If you hypothetically don't know too many nursery rhymes 80's songs work in a pinch. Just replace a few words with baby terms. This mornings example: Safety Dance - replace "dance" with "poop" or "toot" and it instantly helps soothe the baby.
Awww - the Chinese postdoc who I've been coaching on English oral presentations just got back from his dissertation defense. He said the dissertation committee was "stunned" by his progress in the two months since his practice defense. *preens*