where
x equals a
farm animal, and
y equals the
noise it makes:
old macdonald had a farm (e i e i o),
and on that farm he had a(n) x (e i e i o),
with a y, y, here
and a y, y, there
here a y, there a y,
everywhere a y, y,
old macdonald had a farm (e i e i o)!