A vicar goes to see an elderly woman at her home.
She shows him her new parrot.
"I think he used to belong to a vicar." the old lady says.
"Really!" says the vicar. "But why has he got a ribbon tied round each leg?"
"Pull the left one." say the old dear.
He does.
The parrot stands to attention and sings 'All things bright and beautiful."
"That's amazing." says the vicar
"Now pull the right one." the proud owner insists.
He does and the parrot again, stands to attention, and sings 'Abide with me.'
"That's incredible. And what happens if I pull both ribbons at once?" asks the vicar
"I fall off the bloody perch you prat." replies the parrot.