If you lived a long time ago, during the Middle Ages or Renaissance, say, and had yourself tucked away in a castle on a hilltop somewhere in Europe, you probably were accustomed to a life of lavish banquets at long wooden tables bedecked with succulent dishes and ornate tableware. That tableware might well have included knives etched with musical notation on their blades, maybe a cheat sheet of sorts to help get you through those potentially embarrassing moments when you had forgotten the words and melody to sing for the table blessing and for grace. In a video posted on the Web site of London's Victoria and Albert Museum, curator Kristin Kennedy shares an extremely rare notation knife from the museum's collection. The label reading "Tenor" on this knife made Kennedy wonder if knives with music for other voice parts also existed. She looked into it and found so-called notation knives in collections in the United States and around Europe. Kennedy gathered photographs of the knives and transcribed the archaic musical notation on them into modern notes.  Click here to hear musicians at London's Royal College of Music perform the music engraved into the knives' blades. Read more: A Notation Knife (Victoria and Albert Museum)