The Star-Spangled Banner was written by Francis Scott Key in 1814 after witnessing the defence of Fort McHenry, and it became the official national anthem of the United States in 1931. Its melody comes from an older British song, and it is now heard at sporting events, ceremonies and national celebrations. Online, short clips of the anthem have become a handy shorthand for patriotism, satire and exaggerated American pride. Creators also use it as a prank sound, playing it suddenly to catch friends off guard and turn a normal moment into a mock ceremony.