To all of their fans... a question. Every band, singer, or group has one single song that defines who they are -- lyrically, stylistically, and artistically. What is it for Radiohead? Explain why you think so.

Yeah, I know it's hard. But there *is* only just one.

Please note that saying one of their successful singles and/or one of your favorite songs is *not* always the best answer, and I would ask that without a well-defined reason that you try and refrain from doing so. Nonetheless, thank you all for answering.