Gilbert and Sullivan  refers to the Victorian-era theatrical partnership of the librettist W. S. Gilbert (1836–1911) and the composer Arthur Sullivan (1842–1900) and to the works they jointly created.  The two men collaborated on fourteen comic operas between 1871 and 1896, of which H.M.S. Pinafore, The Pirates of Penzance and The Mikado are among the best known.  Gilbert, who wrote the words, created fanciful “topsy-turvy” worlds for these operas where each absurdity is taken to its logical conclusion — fairies rub elbows with British lords, flirting is a capital offence, gondoliers ascend to the monarchy, and pirates turn out to be noblemen who have gone wrong.  Sullivan, six years Gilbert’s junior, composed the music, contributing memorable melodies that could convey both humour and pathos.  Their operas have enjoyed broad and enduring international success and are still performed frequently throughout the English-speaking world.  (More from Wikipedia)