I have Ubuntu 12.04, and it came with Rhythmbox. Now I want to put some music on my computer, so I opened Rhythmbox, and it's displaying a long list of files from various places on my computer. I'm not sure how it decided which files to list - some of them aren't even audio files.
Screenshot: https://i.stack.imgur.com/PzcHV.jpg
I tried going to Edit -> Preferences -> Music -> Library Location, and it said there were multiple locations and wouldn't tell me what they were, so I found this answer and disabled the Ubuntu One plugin and set the library location to a single folder (which currently exists and is empty). This had no effect on what files Rhythmbox listed. Restarting Rhythmbox and restarting my computer also had no effect.