The most famous organ piece in history is one that you've heard a million times, even if you don't know its name, and even if you don't know its composer -- which, spoiler alert, I'll tell you right now: it's the Toccata and Fugue in D minor, by Johann Sebastian Bach. At least, that's the traditional view. But some say that it wasn't written by him at all. Turns out to be a real detective story -- but where will it lead us?