Answer:
a humorous, frequently bawdy, verse of three long and two short lines rhyming aabba, popularized by Edward Lear.
Explanation:
There was a Young Lady of Ryde.
There was a Young Lady whose Bonnet.
There was an Old Man in a Boat.
There was an Old Man in a Tree.
There was an Old Man of Kilkenny.
There was an Old Man of Marseilles.
There was an Old Man of Quebec.
There was an Old Man who Supposed.
There was a young woman named Bright.
There was an odd fellow named Gus.
There once was a fly on the wall.
There once was a man from Tibet.
There was a young woman named Bright.
I need a front door for my hall.
There once was a boy named Dan.
Further (more detailed) example:
There was an Old Man with a beard, Who said, 'It is just as I feared! Two Owls and a Hen, Four Larks and a Wren, Have all built their nests in my beard!