I'm watching the episode of The Simpsons where Bart goes to France, and Bart and his friends say "good morning Mr. Skinner" in a sing song way when Skinner shows up with his mum.
We used to do the same sort of sing song response in my (Australian) school as a kid in the 90s. The teacher would say "good morning class" and we'd all respond with a rather unenthusiastic "gooood morningggg Mr. Smiiiiith"
It seems to be a rather universal "tune", and I'm wondering where it came from. My guess it's just something that evolved naturally, as your voice naturally goes up when saying the "-ning" in "morning", but part of me thinks that there's more to it.
