The Pirate Publisher (final restoration)

It did more than that for Gilbert.  He and Sullivan were upset at the successful pirating of their operetta success "H.M.S. Pinafore" in 1878-79, particularly by theater companies and producers in the U.S.  Gilbert particularly did not like his librettos to be torn up by these pirates, because they were basing their productions on what their agents heard or managed to jot down.  Sullivan was not happy either about the fact that his music was watered down by sea shanties and even rather suggestive songs about women.  So, when they did "The Pirates of Penzance", they rehearsed two companies and sent one to open their production in New York (complete with American copywrite) in December 1879.  This proved very successful (if the item was copywritten in the U.S. you could not legally pirate it here), so that from then on this method was used for all the Savoy Operas.  Still the lack of an international copywrite meant much to both partners (and their third partner Richard D'Oyly Carte).  In 1887, while London was enjoying the "Mikado", Sullivan and his nephew Herbert took a vacation to the U.S. On one of his stops Sullivan was introduced at a theater and took the occasion to thank the Americans for their hospitality, but to insist they should give a writer and a composer as much legal protection wherever he came from on the fruits of his labor as they did a man who invented a new beer tap. 

There was an attempt in the 1970s to give the two men a permanent copywrite (by their admirers) but it failed because the idea is the copywrite (if not renewed) ends after a period of 25 or 40 years, and then the material enters public domain.