The fourth collaboration between Gilbert & Sullivan was their first blockbuster hit: "HMS Pinafore", or "The Lass That Loved a Sailor." This opera opened May 28, 1878 at the Opera Comique. It ran for 571 performances and became a huge fad in England, as well as in America, being copied illegally by dozens of performing companies in the US, as well as being presented there by Gilbert, Sullivan and Carte themselves. Pinafore is among the most popular Gilbert and Sullivan operas, perhaps because of its infectious tunes and generally well-constructed libretto.