Some of classic rock's biggest songs began with musicians fooling around, mocking the music industry, or trying something so ridiculous that nobody expected it to work. Others weren't exactly jokes, but their bizarre origins make their success almost as surprising. From a deliberately terrible love song to a rock anthem invented on a tour bus, these stories reveal just how unpredictable hit-making can be. And in one particularly hilarious case, a band tried to embarrass its record label, only to end up with another smash hit.