By taking influences from a wide range of genres, King Crimson invented their own kind of music which was so hard to place at the time. They weren't ordinary rockers, they were far from jazz, and by no means were they classical. Their dark and challenging outlook invented progressive rock. Protesting the Vietnam war, 21st Century Schizoid Man threw the music world a curveball it didn't know how to catch, but became an important element in heavy metal.