Impending fatherhood has made me think and ponder what I can do to help with a new baby, so I decided nursery rhymes would be my job.
My first entry appears to only be known in the UK despite it having been around for 250 years.
Brought up from the folk tradition of workers complaining about anyone in authority (one of my favourites was "I'm the fat man, the very fat man who waters the workers beer"!)
It is possible that workers using a saw would cut to the rhythm of the rhyme to work faster, given the possibility of two workers at either end of the saw would give credence to this. The workers then taking the rhyme home and singing it to their kids could be how it ended up being a long running nursery rhyme.
See Saw Margery Daw
Johnny shall have a new master
He shall work for a penny a day
Because he can't go any faster
Some other places on the internet use Jenny, Jack, Jackie and even other names, but I've always known it as Johnny so that's correct and don't argue.
Here's a twee video of the rhyme