Oh, life is a glorious cycle of song,
  A medley of extemporanea;
  And love is a thing that can never go wrong;
  And I am Marie of Roumania.

Short, sweet and to the point. The four line poem is one that particularly lends itself to humorous effect - it allows a little more buildup than a couplet, while preserving the added impact that comes from having the punchline coincide with the first rhyme¹.

Examples abound, including several by Nash, Belloc, Bierce, Bentley etc,some of which have been run on Minstrels. And, of course, some lovely ones by Parker herself, of which the one above is probably my favourite - partly for the fine tone of irony, and partly for the ingenuity of the rhyme². And partly, too, for Parker’s particular talent of combining a light, pattering surface, with the bitter undercurrent that runs through nearly all her work.

— Martin

Notes: See poem #150