This was a reply in a thread but it had so many lines I thought I'd post it here.
Q. What goes Fa la?
A. I don't know what does go Fa la?
Q. A Carol singer hit by a bus.
A. What goes Fa la la?
A. Another Carol singer at the next bus stop, just before the bus hit them.
Q. What goes Fa la la la?
A. The Bus.
Q. What goes Fa la la la la, la la la la?
A. A Carol singer waiting for the bus and it hasn't arrived.