There is a nursery rhyme for every occasion. To wit, “Little Boy Blue” is a delightful ditty dedicated to those lazy employees who sleep on the job. Strange? Yes. Accurate? Also yes. Let’s dive in.

Those with French mothers have probably heard this song countless times before bed as children. It’s a coo as much as anything, a portal to drifting off. But what is the origin of the French lullaby, ...