National Metal Day is celebrated on November 11 each year, inspired by the classic metal mockumentary "This Is Spinal Tap." The date, 11-11, symbolizes the iconic scene from the film where the band's amplifiers go "one louder" than 10. The day honors the metal genre, which is characterized by themes of insanity, alienation, and death, while also recognizing its uplifting aspects. Metal music originated in industrial working-class areas of the UK, influenced by British blues rock and the sounds of factories. The genre gained prominence in the late 1960s and early 1970s with bands like Black Sabbath, Led Zeppelin, and Deep Purple. Celebrations typically involve airing metal concerts, specials, and movies, reflecting the genre's rich history and diverse sub-genres, including thrash, death, and black metal.